Appliance interface, system, and method for liquid ingress detection in the appliance interface

ABSTRACT

An electronic system comprising an appliance interface and an electronic device couplable to the appliance interface is disclosed. The appliance interface comprises at least one primary appliance terminal, a reference appliance terminal, and a dielectric region separating the at least one primary appliance terminal and the reference appliance terminal. The electronic device comprises at least one primary device terminal configured to connect to the at least one primary appliance terminal, and a reference device terminal configured to connect to the reference appliance terminal. The electronic device is configured to generate and apply an electrical reference signal to the reference appliance terminal and to detect an electrical primary signal from the at least one primary appliance terminal. Further, the electronic device is configured to compare the primary signal with the reference signal, and, in accordance with at least a component of the primary signal being identical to the reference signal, determine that liquid is present in the appliance interface. Thereby, the electronic system can detect a presence of liquid in the appliance interface: only through the presence of (electrically conducting) liquid in the appliance interface can the primary signal, or a component thereof, be identical to the reference signal. The present disclosure further provides a method for detecting presence of liquid in an appliance interface, an appliance interface, and a medical device comprising the electronic system.

The present disclosure relates to an electronic system for detectingpresence of liquid in an appliance interface. In particular, the presentdisclosure relates to an electronic system comprising an applianceinterface and an electronic device couplable to such applianceinterface. Further, the present disclosure relates a method fordetecting presence of liquid in an appliance interface, and an applianceinterface as such. Further, the present disclosure relates to a medicaldevice comprising an electronic system for detecting presence of liquidin an appliance interface.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of embodiments and are incorporated into and a part ofthis specification. The drawings illustrate embodiments and togetherwith the description serve to explain principles of embodiments. Otherembodiments and many of the intended advantages of embodiments will bereadily appreciated as they become better understood by reference to thefollowing detailed description. The elements of the drawings are notnecessarily to scale relative to each other. Like reference numeralsdesignate corresponding similar parts.

FIG. 1 illustrates an electronic system comprising an electronic deviceand an appliance interface according to an embodiment of the invention,

FIG. 2A illustrates a top view of an appliance interface according to anembodiment of the invention,

FIG. 2B illustrates a top view of an appliance interface according to anembodiment of the invention with a presence of liquid,

FIG. 3A illustrates an exemplary cross-sectional view of an applianceinterface according to an embodiment of the invention,

FIG. 3B illustrates an exemplary cross-sectional view of an applianceinterface according to an embodiment of the invention with a presence ofliquid,

FIG. 4A illustrates a top view of an appliance interface according to anembodiment of the invention,

FIG. 4B illustrates a top view of an appliance interface according to anembodiment of the invention with a presence of liquid,

FIG. 5A illustrates a top view of an appliance interface according to anembodiment of the invention,

FIG. 5B illustrates a top view of an appliance interface according to anembodiment of the invention with a presence of liquid,

FIG. 6A illustrates a sine waveform,

FIG. 6B illustrates a square waveform,

FIG. 6C illustrates a triangular waveform,

FIG. 6D illustrates a sawtooth waveform,

FIG. 7 illustrates a top view of an appliance interface according to anembodiment of the invention,

FIG. 8A illustrates a top view of an appliance interface according to anembodiment of the invention,

FIG. 8B illustrates a cross-sectional view of an appliance interfaceaccording to an embodiment of the invention,

FIG. 9A illustrates a top view of an appliance interface according to anembodiment of the invention with a presence of liquid,

FIG. 9B illustrates a cross-sectional view of an appliance interfaceaccording to an embodiment of the invention with a presence of liquid,

FIG. 10 illustrates a perspective schematic view of an electronic systemaccording to an embodiment of the invention,

FIG. 11 illustrates an exemplary sensor assembly comprising anelectronic system according to an embodiment of the invention, and

FIG. 12 illustrates a close-up view of an appliance interface accordingto an embodiment of the invention.

DETAILED DESCRIPTION

Various exemplary embodiments and details are described hereinafter,with reference to the figures when relevant. It should be noted that thefigures may or may not be drawn to scale and that elements of similarstructures or functions are represented by like reference numeralsthroughout the figures. It should also be noted that the figures areonly intended to facilitate the description of the embodiments. They arenot intended as an exhaustive description of the invention or as alimitation on the scope of the invention. In addition, an illustratedembodiment needs not have all the aspects or advantages shown. An aspector an advantage described in conjunction with a particular embodiment isnot necessarily limited to that embodiment and can be practiced in anyother embodiments even if not so illustrated, or if not so explicitlydescribed.

The use of the word “substantially” as a qualifier to certain featuresor effects in this disclosure is intended to simply mean that anydeviations are within tolerances that would normally be expected by theskilled person in the relevant field.

The use of the word “generally” as a qualifier to certain features oreffects in this disclosure is intended to simply mean—for a structuralfeature: that a majority or major portion of such feature exhibits thecharacteristic in question, and—for a functional feature or an effect:that a majority of outcomes involving the characteristic provide theeffect, but that exceptionally outcomes do no provide the effect.

The present disclosure provides an electronic system for detectingpresence of liquid in an appliance interface, a method for detectingpresence of liquid in an appliance interface, an appliance interface,and a medical device comprising the electronic system.

In a first aspect of the invention, an electronic system for detectingpresence of liquid in an appliance interface is disclosed. Theelectronic system comprises an appliance interface and an electronicdevice couplable to the appliance interface. The appliance interfacecomprises at least one primary appliance terminal, a reference applianceterminal, and a dielectric region separating the at least one primaryappliance terminal and the reference appliance terminal. The electronicdevice comprises at least one primary device terminal configured toconnect to the at least one primary appliance terminal, and a referencedevice terminal configured to connect to the reference applianceterminal. The electronic device is configured to generate and apply anelectrical reference signal to the reference appliance terminal and todetect an electrical primary signal from the at least one primaryappliance terminal. Further, the electronic device is configured tocompare the primary signal with the reference signal, and, in accordancewith at least a component of the primary signal being identical to thereference signal, determine that liquid is present in the applianceinterface.

In the following, the electrical reference signal and the electricalprimary signal is referred to as the reference signal and the primarysignal, respectively. By an electrical signal is meant a signalconveying information composed of a (varying) electrical parameter overtime, such as voltage (V), and/or current (I) as a function of time (t).

By liquid is meant any liquid substance, in particular any electricallyconducting liquid substance, since such liquid is particularly relevantin settings involving electricity. For example, by liquid is meantwater, such as tap water, sea water, body fluids, and liquidsencountered on a daily basis, such as beverages. In embodiments, theelectronic system is configured to detect presence of a conductingmedium in the appliance interface, whereby is meant any substance, fluidor solid, present in the appliance interface.

An appliance interface is used in a variety of different settings, suchas in electrical connectors comprising a plug (male component) and asocket (female component). Thus, by an appliance interface is meant thepoint at which one or more conductors (e.g., electrodes) of anappliance, such as a component, device, or network, comes to an end.Thus, the appliance interface facilitates an electrical (galvanic)connection between an appliance and another component, e.g. theelectronic device according to the first aspect of the invention. Theappliance interface comprises at least one primary appliance terminaland a reference appliance terminal. For example, the appliance interfacecomprises at least two, such as two, primary appliance terminals, and areference appliance terminal.

In embodiments, by an appliance is meant a component, device, ornetwork. In embodiments, the appliance interface is an applianceinterface of a sensor assembly comprising one or more electrodes, suchas two electrodes for each sensor provided in the sensor assembly. Thus,in embodiments, the appliance is a sensor assembly. In embodiments, thesensors are configured to detect changes in resistance/conductanceand/or capacitance, such as when a voltage is applied across two(distinguishable) primary appliance terminals of the appliance interfaceconnected to two electrodes forming a sensor (e.g., one of the twoelectrodes is grounded relative to the other).

In embodiments, the appliance interface comprises/forms part of a plugfor receiving/entering a socket. In embodiments, the appliance interfacecomprises/forms part of a socket for receiving a plug. In embodiments,the appliance interface comprises/forms part of a port for enablingelectrical communication between an electronic device and an appliance,such as a component, device, or network, connected to the applianceinterface. In an embodiment, the appliance interface is substantiallyplanar. Thus, terminals of the appliance interface may be exposedcontact pads/points on a planar surface, the contact pads being adaptedfor receiving corresponding terminals of a corresponding connector, e.g.the electronic device. Providing a planar appliance interface may beparticularly useful for use/incorporation in substantially planarappliances, such as medical devices for attachment to the skin, such asostomy appliances or wound dressings. In embodiments, the applianceinterface (male) is adapted to be inserted into a slit (deviceinterface) formed in the electronic device (female). In embodiments, aclamping mechanism of the electronic device releasably secures theappliance interface in the device interface. In embodiments, the(planar) appliance interface has a thickness less than 5 mm, such as 5mm, 4 mm, or 3 mm, or less than 2 mm, such as 1 mm or 0.5 mm. Inembodiments, the appliance interface extends less than 25 mm in a firstdirection, and less than 25 mm in a second direction being perpendicularto the first direction. Thereby is provided an appliance interface withdimensions <25 mm×<25 mm in a two-dimensional plane, and a thickness <5mm.

In embodiments, by liquid present in the appliance interface is meantthat liquid is present on a surface of the appliance interface, or inthe interface formed between the appliance interface and the electronicdevice, when the latter is coupled to said appliance interface.

Electronic devices are used in a variety of different settings, such asin electrical connectors comprising a plug (male) and a socket (female).In particular, within the present context, the electronic devicecomprises a device interface comprising the corresponding gender to theappliance interface, such that the electronic device (in particular thedevice interface) is couplable to the appliance interface. For example,in embodiments, the appliance interface comprises the male part, and theelectronic device (device interface) comprises the female part, or theappliance interface comprises the female part and the electronic devicecomprises the male part. In a preferred embodiment, the applianceinterface is considered a plug (male part) for the device interface ofthe electronic device (socket, female part). An electronic device withinthe present context can be a device capable of controlling the appliancecomprising the appliance interface, e.g. through a processor and a powerunit embodied in the electronic device. In embodiments, by an electronicdevice within the present context is meant a wireless/cordless personaldevice, i.e. a device easy to handle and having dimensions making itsuitable for attachment to appliances used in everyday life, includingmedical devices, such as ostomy appliances and wound dressings. Inembodiments, the electronic device is a monitor device for receivingsensory inputs, such as from sensors connected to the applianceinterface. In embodiments, a maximum dimension, such as a length, of theelectronic device is 10 cm, or 8 cm, or 6 cm. In embodiments, theelectronic device is crescent-shaped.

Jointly, the appliance interface and the electronic device is denotedthe connectors, where it is envisioned that the appliance interfacecomprises one part of the connectors, and the device interface of theelectronic device comprises the corresponding second part of theconnectors. In the following, the electronic device is said to becouplable to the appliance interface, whereby it is meant that a deviceinterface of the electronic device is couplable to the applianceinterface. In particular, by couplable is meant that a galvanicelectrical connection may be formed between the electronic device andthe appliance interface.

In embodiments, the appliance and the appliance interface thereof areconsidered a passive part, meaning that power, such as voltage, neededto control the appliance is provided by means of the electronic device,which can therefore be considered an active part. Details on theelectronic device is disclosed below.

Presence of liquid in an appliance interface, in particular when coupledto a corresponding connector (e.g., electronic device) and a voltage isapplied, can cause malfunctioning of the connection and/or appliance,and/or risk of injury to the operator/user. Further, the presence ofliquid in the interface can cause interference, false signals, or noise,such that signals pertaining to the appliance are unreliable. Thus, aneed exists to provide detection and determination of the presence ofliquid in the appliance interface when coupled to a correspondingsocket/plug, such as an electronic device. Such ability is particularlydesirable in medical devices, such as ostomy appliances, wounddressings, and urinary catheters, where exposure to body fluids and/orwater (personal hygiene) is a likely outcome of usage. Based on adetection of liquid, remedying actions can be applied, such as byrequesting the user to clean the interface, entering a safe mode of theelectronic device, or disregarding some or all signals pertaining to theappliance, since such signals can be faulty.

The electronic device can be coupled to the appliance interface in avariety of ways, including by means and methods known in the art, suchas suitable mechanical couplings, such as press fit or snap fit. Bycoupled is meant that the electronic device can be coupled to theappliance interface in such a way that an electrical (galvanic)connection between the device and the appliance interface isestablished. In embodiments, the electronic device is releasablycouplable to the appliance interface, such that the electronic devicecan be coupled to the appliance interface and subsequently bedecoupled/detached from the appliance interface. In embodiments, theelectronic device and/or appliance interface are provided with means forsecuring/fastening the connectors together in a coupled configuration,and such that the electronic device and the appliance interface can bedecoupled by actuating a force on a coupling mechanism.

The appliance interface comprises at least one primary applianceterminal. The at least one primary appliance terminal is electricallyconductive. By a primary appliance terminal is meant a terminalconstituting the endpoint of an electrode of the appliance comprisingthe appliance interface. For example, where the appliance interface isan appliance interface of an electrode of a sensor, the primaryappliance terminal constitutes the terminal allowing to control theelectrode, e.g. by means of an electronic device couplable to theappliance interface. The appliance interface comprises at least oneprimary appliance terminal, such as one, two, three, four, five, six,seven, nine, or ten primary appliance terminals. For example, where theappliance comprising the appliance interface comprises N separate parts,such as N electrodes, the appliance interface can be provided with Nprimary appliance terminals, thereby providing means for communicatingseparately with each of the N separate parts, such as N electrodes.

In embodiments, the appliance interface comprises at least two primaryappliance terminals. For example, by providing at least two primaryappliance terminals, one of the at least two primary appliance terminalscan be grounded—by means of the electronic device—relative to theremaining primary appliance terminal(s). In embodiments, one of the atleast two primary appliance terminals is a common ground for theremaining primary appliance terminal(s).

In embodiments, the at least one primary appliance terminal is shaped asa planar contact pad, such that an electrical galvanic connectionbetween an electronic device and the appliance comprising the applianceinterface can be established by bringing a corresponding terminal(contact pad thereof) of the electronic device into physical (galvanic)contact with the contact pad. In embodiments, the contact pad iscircular or rectangular. In embodiments, a maximum dimension of thecontact pad is 10 mm, or 8 mm, or 6 mm, or 5 mm, or 4 mm, or 3 mm, or 2mm, or 1 mm. By providing the at least one primary appliance terminal asa planar contact pad, the appliance interface as such may be provided assubstantially planar. In embodiments, the at least one primary applianceterminal is shaped as a pin configured to engage with a correspondingsocket of the device interface. In embodiments, two or more primaryappliance terminals are arranged adjacent each other but electricallyinsulated from each other. For example, two or more primary applianceterminals are separated (by a dielectric material), such as in a plane,by a distance of at least 0.5 mm, such as 0.5 mm, or at least 1 mm, orat least 2 mm, or at least 3 mm.

The electronic device is configured to detect an electrical primarysignal through the at least one primary appliance terminal. Inembodiments, the primary signal is a composite signal comprising two ormore component signals (in short denoted components). For example, twoor more components of the primary signal can arise from the appliance,such as in a multiplexer configuration. The primary signal can comprisea component signal from the appliance (an appliance signal) and acomponent signal pertaining to the reference signal, such as a componentbeing identical to the reference signal, and hence indicate presence ofliquid (to be described in detail below). Thus, in embodiments,appliance signal(s) and the reference signal are superimposed. In thefollowing, a reference to appliance signal (singular) can likewise be areference to appliance signals (plural) and vice versa, unless otherwisespecified or understood from the context.

In embodiments, the at least one primary appliance terminal isconfigured to transmit/relay/output electrical signals to/from theappliance comprising the appliance interface. In the following, signalsarising/pertaining to the appliance comprising the appliance interfaceare denoted appliance signal(s). Thus, the primary appliance terminal isconfigured to output/input a composite signal, the composite signalcomprising appliance signals (one or more components) and, in accordancewith the presence of liquid in the appliance interface, a componentpertaining to the reference signal. If the component pertaining to thereference signal (i.e., the component being identical to, or comprises acharacteristic of, the reference signal) is present in the (composite)primary signal, it is indicative of a presence of liquid. This isdescribed further in the following. If liquid is not present in theappliance interface, the primary signal can either be absent (if noappliance signals are generated by the appliance), or the primary signalcan comprise appliance signal(s) only. In other words, the referencesignal is detectable in the primary signal.

The appliance interface comprises a reference appliance terminal. Thereference appliance terminal is electrically conductive. In embodiments,the reference appliance terminal does not constitute an endpoint of anappliance comprising the appliance interface. Rather, the referenceappliance terminal is provided in/on the appliance interface but is notconfigured to establish an electrical connection between the electronicdevice coupled to the appliance interface and an electrode of theappliance comprising the appliance interface. Thus, in embodiments, thereference appliance terminal is electrically insulated from any otherconductive parts (in particular the at least one primary applianceterminal) of the appliance interface and parts of the applianceconnected thereto. In embodiments, the reference appliance terminal isshaped as a planar contact pad, such as shaped identically to the atleast one primary appliance terminal. In embodiments, the referenceappliance terminal is shaped as a pin. The reference appliance terminalis configured to receive a reference signal from, and generated by, theelectronic device when the latter is coupled to the appliance interface.In embodiments, multiple, such as at least two, reference applianceterminals are provided in the appliance interface, such as to provide aback-up reference appliance terminal in case of failure of a firstreference appliance terminal, or to provide a control.

A dielectric region separates the at least one primary applianceterminal and the reference appliance terminal, such as a planardielectric region where the appliance interface is planar and comprisesplanar contact pads. Thereby, at least in a dry state of the applianceinterface, electrical signals (e.g., current) cannot be transmitted(e.g., flow) to/from the reference appliance terminal from/to the atleast one primary appliance terminal. In embodiments, a dielectricregion encloses each of the at least one primary appliance terminals. Byenclose is meant to surround, such as in the plane, each of the at leastone primary appliance terminals, e.g. when the appliance interface issubstantially planar, and when seen in a direction normal to the planeof the appliance interface. Thus, by enclose is not meant to encapsulateand thereby fully insulate the at least one primary appliance terminalfrom the entire surroundings.

In embodiments, the dielectric region serves to insulate the at leastone primary appliance terminal from another (if provided) and/or toinsulate the at least one primary appliance terminal from the referenceappliance terminal. For example, where the at least one primaryappliance terminal is a planar contact pad, the dielectric region can beprovided along the periphery of such contact pad, such as within 1 mm ofthe periphery of the primary appliance terminal. In embodiments,multiple dielectric regions are provided, such as when the (planar)appliance interface comprises two or more primary appliance terminals, a(planar) dielectric region can surround/enclose each of said two or more(planar) primary appliance terminals. Thus, in embodiments, a dielectricregion exists for each of the primary appliance terminals.

In embodiments, the dielectric region comprises a dielectric material,such as a dielectric (co)polymer material, such as a (co)polymermaterial not capable of absorbing liquids, such as isobornyl acrylate.In embodiments, the dielectric region comprises oxides or nitrides, suchas silicon dioxide and silicon nitride, or similar dielectric materialsknown and used for their dielectric properties in planar (silicon)processing. In embodiments, the dielectric region comprises a dielectricceramic material. In embodiments, the dielectric material is printable,such as to provide fast and easy manufacturing. In embodiments, thedielectric material forms a substrate for the terminals, such that theterminals are provided, e.g., printed, on a surface of the dielectricmaterial. In embodiments the dielectric material is stretchable,flexible, bendable, and/or resilient, such as to provide a flexibleappliance interface. In embodiments, the stretchability is provided bythe dielectric material being an adhesive composition.

The electronic device comprises at least one primary device terminal anda reference device terminal. The at least one primary device terminaland the reference device terminal are electrically conductive. The atleast one primary device terminal is configured to connect to the atleast one primary appliance terminal, and the reference device terminalis configured to connect to the reference appliance terminal. By connectis meant to establish a (physical, galvanic) electrical connectionbetween the respective terminals such as to facilitate transmission ofelectrical signals. In embodiments, the device terminals (primary andreference terminals) connect/mate with the appliance terminals (primaryand reference terminals) in a one-to-one manner, such that theelectronic device comprises the same number of terminals as theappliance interface. In embodiments, the appliance interface and theelectronic device comprises a different total number of terminals, butat least a primary device terminal configured to connect to a primaryappliance terminal, and a reference device terminal configured toconnect to a reference appliance terminal. The at least one primarydevice terminal and the reference device terminal are electricallyinsulated from each other, e.g. by a device dielectric region.

In embodiments, the at least one primary device terminal and thereference device terminal are equal or corresponding in shape to the atleast one primary appliance terminal and the reference applianceterminal. In embodiments, the device terminals are resilient orsupported by a spring to force the terminals into contact with theappliance terminals.

In embodiments, the at least one primary device terminal is connected toa first circuitry of the electronic device, and the reference deviceterminal is connected to a second circuitry of the electronic device. Inembodiments, the first circuitry is configured to apply a voltage acrosstwo or more primary terminals or to gather electrical primary signalsfrom the at least one primary appliance terminal. In embodiments, thesecond circuitry is configured to generate a reference signal to beconducted to the reference appliance terminal. In embodiments, thecircuitries are controlled by a processor.

In embodiments, the terminals, including the at least one primaryappliance terminal, the reference appliance terminal, the at least oneprimary device terminal, and the reference device terminal comprise oneor more of metallic (e.g. silver, copper, gold, titanium, aluminium,stainless steel), ceramic (e.g. ITO), polymeric (e.g. PEDOT, PANI, PPy),and carbonaceous (e.g. carbon black, carbon nanotube, carbon fibre,graphene, graphite) materials. In embodiments, the at least one primaryappliance terminal and the reference appliance terminal are made of aprintable material, such as silver and/or a carbonaceous material, suchas carbon. In embodiments, the at least one primary appliance terminaland the reference appliance terminal are flexible, bendable and/orstretchable, such as to provide a stretchable appliance interface, e.g.when printed onto a flexible/bendable/stretchable dielectric materialforming a substrate for said terminals.

In embodiments, the electronic device comprises a housing, a processor,a memory, a power unit, and a circuitry. The power unit can beconfigured to apply a voltage across two or more terminals, such as toground one of the two or more terminals relative to the remainingterminal(s). In embodiments, the power unit comprises a battery. Inembodiments, the power unit comprises a charging circuitry connected tothe battery and terminals of a charging interface for charging thebattery via the charging interface. In embodiments, the charginginterface is the device interface, such that the battery can be chargedby coupling the electronic device to a charger unit. In embodiments, twoor more terminals of the device interface are configured to charge thebattery.

In embodiments, the electronic device comprises a sensor unit with oneor more sensors. The sensor unit is connected to the processor forfeeding sensor data to the processor. In embodiments, the sensor unitcomprises an accelerometer for sensing acceleration and provision ofacceleration data to the processor. In embodiments, the sensor unitcomprises a temperature sensor for provision of temperature data to theprocessor.

In embodiments, the electronic device comprises a transmissioninterface. In embodiments, the transmission interface is configured asan accessory interface for connecting, e.g. wirelessly connecting, theelectronic device to one or more accessory devices. In embodiments, thetransmission interface comprises an antenna and a wireless transceiver,e.g. configured for wireless communication at frequencies in the rangefrom 2.4 to 2.5 GHz. In embodiments, the wireless transceiver is aBluetooth transceiver, i.e. the wireless transceiver can be configuredfor wireless communication according to a Bluetooth protocol, e.g.Bluetooth Low Energy, Bluetooth 4.0, and/or Bluetooth 5. An accessorydevice can be a mobile phone, e.g. smartphone, or other handheld device,or a wearable, such as a watch or other wrist-worn electronic device.Thereby, the electronic device of the present disclosure can beconfigured to communicate with an accessory device, such as to allowsuch accessory device to visualize data gathered by the electronicdevice, e.g. when the latter is coupled to an appliance comprising anappliance interface as disclosed. In embodiments, the transmissioninterface comprises a loudspeaker and/or a haptic feedback element forprovision/transmission of an audio signal and/or haptic feedback to auser, respectively.

The electronic device is configured to generate and apply a referencesignal to the reference appliance terminal through the reference deviceterminal. In embodiments, by generating and applying a signal to thereference appliance terminal is meant that the electronic device isconfigured to generate such signal and to conduct the signal to thereference device terminal. When the electronic device is coupled to theappliance interface, an electrical connection between the referencedevice terminal and the reference appliance terminal is established,whereby the signal is conducted to the reference appliance terminal.Thus, in embodiments, by being configured to is meant that theelectronic device can couple to the appliance interface in such a waythat an electrical connection between the reference device terminal andthe reference appliance terminal is established. In embodiments, thesignal is generated by means of a driver or the processor and the powerunit, such that the power unit provides the sufficient current orvoltage, and the driver or processor generates an appropriate referencesignal. In preferred embodiments, the reference signal has a certaincharacteristic, such as a certain electrical waveform or a certainfrequency, making it a distinguishable component signal of a possiblecomposite primary signal.

The electronic device is configured to detect a primary signal from theat least one primary appliance terminal through the at least one primarydevice terminal. In embodiments, by detecting a signal from the at leastone primary appliance terminal is meant that the electronic device isconfigured to detect such a signal, e.g. by detecting changes in currentor voltage over time indicative of such signal. When the electronicdevice is coupled to the appliance interface, an electrical connectionbetween the primary appliance terminal and the primary device terminalis established, whereby a signal can be conducted from said primaryappliance terminal to said primary device terminal. Thus, inembodiments, by being configured to is meant that the electronic devicecan couple to the appliance interface in such a way that an electricalconnection between the primary appliance terminal and the primary deviceterminal is established.

In embodiments, the primary signal is a composite signal comprising acomponent (appliance) signal from the appliance and a component signalfrom the reference appliance terminal (such component signal being thereference signal if liquid in the appliance interface provides a liquidpath/bridge for conducting the reference signal from the referenceappliance terminal to the primary appliance terminal). In embodiments,such as in a dry state of the appliance interface, the primary signalmay comprise component signal(s) from the appliance (appliancesignal(s)) only.

As previously described, the electronic device is configured to comparethe primary signal, or components thereof, with the reference signal.Thus, electronic device is configured to compare the two signals anddetermine their resemblance. In embodiments, the electronic device isconfigured to identify a component signal of the primary signal, and tocompare such component signal with the reference signal. If at least acomponent of the primary signal is identical to the reference signal(e.g., if at least a component of the primary signal shares a certaincharacteristic with the reference signal), it is indicative of liquid inthe appliance interface.

Alternatively, in embodiments, the electronic device is configured tocompare the primary signal, or components thereof, with the referencesignal, and, in accordance with at least a component of the primarysignal comprising a characteristic pertaining to the reference signal,determine that liquid is present in the appliance interface. Forexample, the characteristic can be a certain feature of the referencesignal not expected to be generated by the appliance. Thus, the presenceof the characteristic pertaining to the reference signal is indicativeof liquid in the appliance interface.

According to embodiments, only through the presence of (electricallyconducting) liquid in the appliance interface can the primary signal, ora component thereof, be identical to the reference signal or comprise acharacteristic pertaining to the reference signal. In other words, sincethe reference appliance terminal is (structurally and electrically)separated/insulated from the primary appliance terminal by a dielectricregion, a resemblance between the reference signal and the primarysignal (or component thereof) indicates a presence of liquid: the liquidbridges from the reference appliance terminal to the primary applianceterminal and thereby facilitates the conduction of the reference signalfrom the reference appliance terminal to the primary appliance terminal,whereby the primary signal (or a component thereof) is identical to, orcomprises a characteristic of, the reference signal. In embodiments,resemblance is determined within a certain time period, such as bycomparing the past (trailing) 1 second (or other, such as between 0.1second and 30 seconds, such as 10 seconds) of the primary signal withthe past (trailing) 1 second (or other, such as between 0.1 second and30 seconds, such as 10 seconds) of the reference signal.

In embodiments, by identical is meant that the signals share a strongresemblance, such as at least 80%, or at least 90%, of the measuringpoints are coinciding. In embodiments, by identical is meant that acharacteristic, such as a waveform, of, or contained in, the primarysignal (or a component thereof) resembles the characteristic, such asthe waveform, of the reference signal, in a qualitative and/orquantitative manner. By a qualitative manner is meant that a personskilled in the art (and/or an artificial intelligence (AI) sufficientlytrained in the specific use) is capable of identifying and/ordistinguishing the characteristic, such as the waveform, from noiseand/or appliance signals in a composite signal. Thus, the referencesignal (i.e., the characteristics, such as the waveform, thereof) ispurposively (pre-)selected to be distinguishable, e.g. by software ofthe electronic device and/or by a skilled person, from appliance signalscontained in the (composite) primary signal. For example, the referencesignal can be selected by the software of the electronic device, such asthrough machine learning considering the appliance signals and, overtime, generates a reference signal easily distinguishable from theappliance signals contained in the composite primary signal.Alternatively, the reference signal is selected by the manufacturer ofthe electronic system, e.g. through the manufacturer's knowledge of theexpected appliance signals.

Thereby is provided an electronic system for detecting presence ofliquid in an appliance interface of the electronic system—a water/liquidingress detection system. The disclosed electronic system is aplug-and-socket type of system, where the means for detecting suchpresence of liquid is shared between a (passive) appliance interface andan (active) electronic device couplable thereto.

In alternative embodiments, the electronic device is configured to applya reference signal to the primary appliance terminal and to detect aprimary signal from the reference appliance terminal, i.e., theabove-outlined process in reverse. Thus, in embodiments, the processoutlined above works in reverse, and the same principles and conclusionsapply.

In an embodiment, the reference signal has a first electrical waveform.

By an electrical waveform (also referred to as waveform only), is meantthat the voltage, current, or electromagnetic field associated with the(electrical) signal varies (e.g., periodically) in time. The waveformcan be either periodic or irregular. In embodiments, the referencesignal is an alternating electrical signal.

In embodiments, the waveform is generated by means of a driver or theprocessor controlling the power unit, such that the power unit providesthe sufficient variances in voltage, current, or electromagnetic fieldrepresenting the selected waveform.

In embodiments, the first electrical waveform has a unique or unusualwaveform unlikely to be caused/generated by the appliance, i.e.,unlikely to be contained in the appliance (component) signal of theprimary signal. Thus, in embodiments, the waveform constitutes acharacteristic of the reference signal. Thereby is provided means fordistinguishing the reference signal from appliance signal(s) in the(composite) primary signal. In other words, in embodiments, theelectronic device is configured to look for the specific(unique/unusual) first electrical waveform in the primary signalpotentially also comprising appliance signals. Thus, appliance signalscan be detected and analysed and a presence of liquid in the applianceinterface can be detected simultaneously (i.e., the electronic devicesearches for the reference signal in the primary signal while detectingand analysing appliance signals). In alternative embodiments, noappliance signals are generated while searching for the reference signalin the primary signal. As was also discussed above, a presence of liquidcan be determined upon detection of (at least a component of) theprimary signal being identical to the reference signal. In embodiments,the electronic device is configured to control (e.g. to apply a voltageor current and detect changes thereof/detect appliance signals) theappliance while simultaneously applying the electronic system asdisclosed, i.e. detecting presence of liquid in the appliance interface.Whereas appliance signals can comprise noise and/or certaincharacteristics pertaining to the appliance, the first electricalwaveform of the reference signal can be selected such that it isdistinguishable (in particular its characteristics, such as itswaveform) from expected appliance signals arising from the appliance.Thereby is provided means for simultaneously controlling the electronicsystem for detecting presence of liquid in the appliance interface andcontrolling the appliance.

In embodiments of the appliance interface comprising two or more primaryappliance terminals, the electronic device is configured to eithersimultaneously or consecutively search the primary signal for thecomponent signal pertaining to the reference signal. Thus, inembodiments, the electronic device is configured to detect and analyseprimary signals pertaining to two or more primary appliance terminalssimultaneously. In embodiments, the electronic device is configured todetermine which primary appliance terminal is exposed to liquid in theappliance interface, and, optionally, disregard the specific primarysignal pertaining to this primary appliance terminal and thus theconnected electrode of the appliance.

In an embodiment, the first electrical waveform is selected from a sinewaveform, a square waveform, a rectangular waveform, a triangularwaveform, and a saw-toothed waveform.

In embodiments, the waveform of the reference signal is selected basedon the expected appliance signals arising from the appliance comprisingthe appliance interface, such that the selected waveform is a waveformnot expected to be found in the appliance signals. Thereby, the selectedwaveform can be distinguished from the appliance signals, for thereasons and benefits discussed above.

In embodiments, the electronic device can adapt the waveform of thereference signal over time, e.g. as a result of a machine learningalgorithm considering the appliance signals and designing a waveform, orselecting a pre-stored waveform, distinguishable from such appliancesignals, e.g. such that it is at least distinguishable to the softwareof the electronic device. In embodiments, the waveform is selected bythe manufacturer of the electronic system and/or the appliance. Forexample, the manufacturer can select a waveform generally known fromexperience and/or testing not to be found in the appliance signals.

In embodiments, periodic waveforms are preferred, such as the waveformsoutlined below.

A sine waveform f(t, λ, a, ϕ) can be represented as

${f\left( {t,\lambda,a,\phi} \right)} = {a\sin\frac{{2\pi t} - \phi}{\lambda}}$

A square (and rectangular, with modifications to duty) waveform g(t, λ,a, ϕ) can be represented as

${{\mathcal{g}}\left( {t,\lambda,a,\phi} \right)} = \left\{ \begin{matrix}{a,} & {{\left( {t - \phi} \right){mod}\lambda} < {duty}} \\{{- a},} & {otherwise}\end{matrix} \right.$

A triangular waveform h(t, λ, a, ϕ) can be represented as

${h\left( {t,\lambda,a,\phi} \right)} = {\frac{2a}{\pi}\arcsin\sin\frac{{2\pi t} - \phi}{\lambda}}$

A saw-toothed waveform k(t, λ, a, ϕ) can be represented as

${k\left( {t,\lambda,a,\phi} \right)} = {\frac{2a}{\pi}\arctan\tan\frac{{2\pi t} - \phi}{2\lambda}}$

In the above equations, t is time, λ is wavelength, a is amplitude and ϕis phase. The wavelength (frequency), amplitude and phase can bemodified/selected to further make the reference signal distinguishablefrom the appliance signals.

In an embodiment, the reference appliance terminal comprises a contactpad and an enclosing portion. The enclosing portion at least partlyencloses the at least one primary appliance terminal.

The contact pad and the enclosing portion are both electricallyconductive and connected, such that electrical signals can beconducted/transmitted from the contact pad and into the enclosingportion, and vice versa.

In embodiments, the contact pad is planar. In embodiments, the applianceinterface is planar, such that the contact pad may flush with othercontact pads, such as contact pads of one or more primary applianceterminals. In embodiments, the enclosing portion is planar, such thatthe enclosing portion at least partly encloses the at least one primaryappliance terminal in the plane of the appliance interface.

In embodiments, by enclosing is meant to surround the at least oneprimary appliance terminal, e.g. in embodiments where the applianceinterface is substantially planar, such that when seen in a directionnormal to the plane of the appliance interface (i.e., a top view,looking down at the appliance interface), the enclosing portion at leastpartly surrounds/encloses the at least one primary appliance terminal (adielectric region still separates the at least one primary applianceterminal from the enclosing portion). Thus, for illustrative purposes,the enclosing portion may resemble an arm/leg or a tentacle forincreasing the reach of the contact pad of the reference applianceterminal.

In embodiments, the contact pad of the reference appliance terminal isshaped and dimensioned to resemble the at least one primary applianceterminal, such as a contact pad of the at least one primary applianceterminal.

In embodiments, the enclosing portion comprises one or more legsextending from the contact pad and at least partly encloses the at leastone primary appliance terminal, such as in the plane. For example, inembodiments where the appliance interface comprises a substantiallyplanar surface with the appliance terminals arranged thereupon, the legscan be arranged along, e.g. parallel to, at least one, or at least twoedges of the at least one primary appliance terminal. Thereby, a liquidcan be detected according to the first aspect of the invention if itforms a bridge across the dielectric region from a leg of the referenceappliance terminal to the at least one primary appliance terminal.Thereby, the reference signal can be conducted from the electronicdevice through the contact pad, into the leg, through the liquid, andeventually be contained in the primary signal. Thus, the enclosingportion increases the ability of the electronic system to detect apresence of liquid, since liquid can form a bridge from any point of aleg connected to the contact pad of the reference appliance terminal tothe primary appliance terminal.

In embodiments, the enclosing portion is a coherent region/surface ofthe appliance interface. In corresponding embodiments, the dielectricregion surrounds the (immediate vicinity of) each of the at least oneprimary appliance terminals, such that the remaining surface of theappliance interface (in embodiments of this being planar as discussedpreviously) is covered by the enclosing portion of the referenceappliance terminal. In other words, in embodiments, a dielectric regionencloses each of the at least one primary appliance terminals.

A designated part of the enclosing portion can be considered to be thecontact pad where the reference device terminal is configured totouch/form an electrical connection to the reference appliance terminal.For example, the contact pad can be considered a reinforced region ofthe reference appliance terminal, which otherwise comprises theenclosing portion. Thereby, a conducting liquid merely needs to bridgeacross the dielectric region surrounding the immediate vicinity of theat least one primary appliance terminal. In embodiments, by immediatevicinity is meant that the dielectric region extends less than 3 mm awayfrom a periphery of the at least one primary appliance terminal, such asless than 1 mm. Thus, by providing the enclosing portion as a coherentregion/surface covering a substantial portion of the appliance interface(e.g., more than 25% or more than 50% of the surface area of theappliance interface in embodiments of the appliance interface beingplanar), presence of liquid is increasingly likely to be detected.

In an embodiment, the reference device terminal is configured to connectto the contact pad of the reference appliance terminal.

In embodiments, the contact pad is a designated area of the enclosingportion of the reference appliance terminal, such as a reinforceddesignated area. In embodiments, by reinforced is meant that the contactpad is made of a different conductive material than the enclosingportion, such as a more durable conductive material than the enclosingportion, or the contact pad may be provided with a thicker layer ofconductive material, such that the contact pad is configured to be inphysical (galvanic) contact with the reference device terminal withoutcausing degradation of the contact pad.

In an embodiment, the at least one primary appliance terminal is aterminal of an electrode of a sensor. Thus, in embodiments, theappliance comprising the appliance interface and hence the at least oneprimary appliance terminal is a sensor, such as a sensor assemblycomprising at least one sensor.

In embodiments, the primary appliance terminal is the endpoint of anelectrode of a sensor. In embodiments, the appliance interface comprisesa plurality of primary appliance terminals, such as two or more primaryappliance terminals, forming the endpoint of a plurality of electrodes,such as two or more electrodes, of, or for, a sensor. In embodiments,the at least one primary appliance terminal is a terminal of anelectrode of a sensor of a sensor assembly. In embodiments, a sensorcomprises two electrodes. In embodiments, the electronic device isconfigured to apply a voltage across the two electrodes of a sensor(e.g., to ground one of the two electrodes relative to the other) and tomonitor changes in relevant electrical parameters, such as resistance orcapacitance, in order to sense changes in the environment/surroundingsof the sensor (sensor assembly).

In embodiments, the appliance, such as the sensor assembly, issubstantially planar. In embodiments, the sensor assembly and theappliance interface are arranged in the same geometrical plane. Inembodiments, the sensor assembly is stretchable/flexible. Inembodiments, the electrode(s) of the sensor assembly is arranged, e.g.printed, on a stretchable substrate, such as a polymer material. Inembodiments, the appliance interface and the electrode(s) of the sensorassembly are printed in a single process, e.g. printed on a supportlayer/film. In an embodiment, the appliance interface is arranged on astretchable substrate. By a stretchable substrate is meant a flexibleand/or elastic substrate, such as a polymer material or an adhesivematerial for a medical device, such as a base plate for an ostomyappliance, or a wound dressing. In embodiments, the stretchablesubstrate comprises the dielectric region of the appliance interface.

In embodiments, the adhesive material, e.g. an adhesive layer, is madeof a first composition. In embodiments, the first composition comprisesone or more polyisobutenes and/or styrene-isoprene-styrene. Inembodiments, the first composition comprises one or more hydrocolloids.In embodiments, the first composition comprises one or more watersoluble or water swellable hydrocolloids. In embodiments, the firstcomposition is a pressure sensitive adhesive composition suitable formedical purposes comprising a rubbery elastomeric base and one or morewater soluble or water swellable hydrocolloids. In embodiments, thefirst composition comprises one or more polybutenes, one or more styrenecopolymers, one or more hydrocolloids, or any combination thereof. Thecombination of the adhesive properties of the polybutenes and theabsorbing properties of the hydrocolloids renders the first compositionsuitable for use in ostomy appliances. For example, the styrenecopolymer can be a styrene-butadiene-styrene block copolymer or astyrene-isoprene-styrene block copolymer. Preferably, one or morestyrene-isoprene-styrene (SIS) block type copolymers are employed. Theamount of styrene block-copolymer can be from 5% to 20% of the totaladhesive composition. The butene component is suitably a conjugatedbutadiene polymer selected from polybutadiene, polyisoprene. Thepolybutenes are preferably present in an amount of from 35-50% of thetotal adhesive composition. Preferably, the polybutene ispolyisobutylene (PIB). Suitable hydrocolloids for incorporation in thefirst composition are selected from naturally occurring hydrocolloids,semisynthetic hydrocolloids, and synthetic hydrocolloids. The firstcomposition can comprise 20-60% hydrocolloids. A preferred hydrocolloidis carboxymethyl cellulose (CMC). Optionally, the first composition cancontain other components, such as fillers, tackifiers, plasticizers,and/or other additives.

In embodiments, the sensor (the sensor assembly) is embedded in amedical device, such that the sensor is provided as an integral part ofthe medical device. For example, the sensor can be fixed/incorporatedwithin the material forming at least part of the medical device.

In embodiments, the medical device is an ostomy appliance. Inembodiments, the ostomy appliance comprises a base plate comprising anadhesive layer for adhering the base plate to a peristomal skin surfaceof a user having an ostomy. In embodiments, the sensor assembly isconfigured to surround the ostomy and to detect moisture absorption inthe first adhesive layer and/or to detect presence of liquid (such asoutput emanating from the ostomy) in the interface between the adhesivelayer and the peristomal skin surface of the user. For example, thesensor assembly can be provided on a distal and/or proximal surface ofthe adhesive layer (by proximal is meant arranged closest to the skinsurface, relative to another element (thus being distal), when worn by auser), e.g. sandwiched between a distal surface of the adhesive layerand a proximal surface of a polymeric top film protecting the adhesivelayer.

In embodiments, the medical device is a wound dressing. In embodiments,the sensor assembly provides for detecting presence and/or propagationof exudate in the vicinity of a wound covered by the wound dressing. Forexample, the sensor assembly can be provided on a distal and/or proximalside of an absorbent core (by proximal is meant arranged between theabsorbent core and the wound) of such wound dressing, e.g. sandwichedbetween a distal side of the absorbent core and a proximal side of apolymeric top film protecting the absorbent core.

In an embodiment, the appliance interface is disposable, and theelectronic device is reusable. In embodiments, the appliance and theappliance interface thereof are disposable. For example, where theappliance is a sensor assembly embedded in a base plate of an ostomyappliance or in a wound dressing, it is desired to provide such baseplate or wound dressing as a disposable item, e.g. a single-use item. Bybeing couplable to the appliance interface, the electronic device can bedecoupled and re-coupled to a new appliance interface of new applianceafter disposal of the earlier appliance. Thereby, relatively expensiveelectronics can be provided in the electronic device, whereas the costsof the appliance interface and the associated appliance can be reducedto a minimum. Thereby is provided an electronic system comprising twoparts, wherein one part is disposable and relatively cheap (theappliance interface, also referred to as a passive part), and wherein asecond part is reusable and relatively expensive (the electronic device,also referred to as an active part), and wherein the electronic systemretains the ability to detect a presence of liquid in the applianceinterface. In embodiments, the appliance interface is planar, aspreviously discussed, in order to be provided in a planar appliance,such as a base plate or a wound dressing. Thereby, the electronic deviceand the appliance interface may be coupled in the plane of theappliance, thereby reducing the bulk size of the appliance when in use.

In an embodiment, the appliance interface comprises a first primaryappliance terminal and a second primary appliance terminal, and theelectronic device comprises a first primary device terminal and a secondprimary device terminal. In embodiments, the first primary deviceterminal is configured to establish an electrical connection to thefirst primary appliance terminal, and the second primary device terminalis configured to establish an electrical connection to the secondprimary appliance terminal. Thus, in addition to the appliance/devicereference terminal, the appliance interface/electronic device comprise afirst and a second primary appliance/device terminal.

In embodiments, the appliance interface comprises more than two primaryappliance terminals, such as a third, a fourth, a fifth, a sixth, aseventh, an eight, a ninth, and/or a tenth primary appliance terminal.Correspondingly, in embodiments, the electronic device comprises morethan two primary device terminals, such as a third, a fourth, a fifth, asixth, a seventh, an eight, a ninth, and/or a tenth primary deviceterminal. In embodiments, the primary appliance terminals are configuredto contact the primary device terminals in a one-to-onemanner/configuration.

In an embodiment, the electronic system further comprises an applianceconnected to the appliance interface. In embodiments, the appliance is abase plate of an ostomy appliance, a sensor patch for attachment to theproximal surface of a base plate, or a wound dressing, as previouslydiscussed. According to the embodiment, the first primary applianceterminal is a terminal of a first electrode of the appliance, and thesecond primary appliance terminal is a terminal of a second electrode ofthe appliance. By connected to the appliance interface is meant that theappliance interface is an appliance interface of the appliance, suchthat the appliance and the appliance are electrically connected. Inembodiments, the appliance is, or comprises, a sensor assembly. Inembodiments, jointly, the first and the second electrode form a sensorof the sensor assembly. In embodiments, an electrode is a conductivewire or path, such that electricity or a voltage can be applied thefirst and the second electrode. In embodiments, electrodes are printableon a support layer, such as printable in a continuous process along withthe terminals of the appliance interface.

According to the embodiment, the appliance interface comprises a firstand a second primary appliance terminal, which, in combination withprevious embodiments, are electrically connectable/couplable tocorresponding first and second device terminals of the electronicdevice. Thereby, the electronic device can read and/or control (e.g.,apply a voltage across) each of the first and second electrodesconnected to the first and second appliance terminals, respectively,individually/independently. In other words, the primary applianceterminals are distinguishable to the electronic device.

In embodiments, the electronic device is a monitor device configured tomonitor changes in one or more electrical quantities/parameters, such asvoltage, resistance, resistivity, conductance, conductivity, and/orcapacitance, pertaining to the electrodes of the appliance (e.g., asensor). Such changes in electrical parameters can be attributed changesin the environment of the appliance (sensor), and thus provide valuableinformation to the electronic device, which can be analysed andcommunicated to a user of the device. For example, the electronic devicemay be configured to detect presence of stomal output on a proximalsurface of a base plate, presence of moisture in the adhesive layer of abase plate, or the presence of exudate uptake in a foam material of awound dressing.

In an embodiment, the electronic device is configured to apply a voltageacross the first primary appliance terminal and the second primaryappliance terminal. In embodiments, the first and the second primaryappliance terminals are endpoints of a first and a second electrode,respectively, of the appliance, such as of a sensor assembly. Thus, byapplying a voltage across the first and the second primary applianceterminal, a voltage is applied across the first and the secondelectrode. In embodiments, the two electrodes form a sensor. Inembodiments, the electrodes are provided in a non-conductive medium or aliquid-absorbing medium, or exposed to the surroundings. In embodiments,the non-conductive medium or the liquid-absorbing medium is an adhesivecomposition, such as an adhesive layer of a medical device, such as abase plate of an ostomy appliance.

By applying a voltage across the electrodes, it is possible to monitorchanges in the resistance in the non-conductive medium or theliquid-absorbing medium or the surroundings, the resistance beingindicative of physical or chemical changes in the medium or thesurroundings. Thereby is provided a sensor (sensor assembly) having anappliance interface as described, and the sensor being configured todetect changes in resistance indicative of changes in the surroundings,and the appliance interface being configured to detect presence ofliquid according to the first aspect of the invention.

In an embodiment, the electronic device is configured to detect ashort-circuit across the first primary appliance terminal and the secondprimary appliance terminal. When applying a voltage across theterminals, and hence electrodes thereof, it is possible that liquidbridging across the electrodes causes a short-circuit. Such presence ofliquid can be indicative of changes in the surroundings of theelectrodes (sensor) of the appliance, and hence be valuable informationto the user, e.g. where such presence of liquid is unwanted, e.g. in theinterface between a peristomal skin surface of a user and a firstadhesive layer of a base plate of an ostomy appliance.

In an embodiment, the electronic device is configured to, in accordancewith a detection of a short-circuit across the first primary applianceterminal and the second primary appliance terminal, determine thatliquid is present in/near the appliance. In embodiments, the applianceis a sensor assembly as described above.

The occurrence/detection of a short-circuit across two primary applianceterminals can be caused by two different events: either due to liquidbridging across electrodes in the appliance (e.g. a sensor of the sensorassembly) connected to the two primary appliance terminals (which can bea desired functionality of the monitor aspect of the electronic device),or due to liquid in the appliance interface bridging from one primaryappliance terminal to another (which is unwanted due to reasonspreviously disclosed and an object of the first aspect of theinvention). However, due to the electronic device being capable ofapplying a reference signal to the reference appliance terminal, comparea detected primary signal with the reference signal and determining ifliquid is present in the appliance interface based on the resemblancebetween the signals, it is possible to distinguish a short-circuitacross the electrodes of the appliance from a short-circuit due toliquid in the appliance interface. In other words, presence of liquid inthe appliance interface is detected by means different from detecting ashort-circuit, meaning that the detection of a short-circuit can beattributed to the appliance comprising the appliance interface ratherthan the primary appliance terminals of the appliance interface as such.In further other words, the electronic system according to theembodiment is configured to differentiate a short-circuit in theappliance comprising the appliance interface from a short-circuit in theappliance interface as such (e.g. due to the presence of liquid in saidappliance interface). The ability to differentiate such short-circuitrelies on the application, detection, and comparison of electricalsignals having a certain characteristic, such as a certain waveform. Itis appreciated that whereas a short-circuit is discussed, the presentdisclosure may also facilitate the detection of minor changes inelectrical characteristics of the electrodes of the appliance, and thatsuch minor changes may likewise be differentiated from the signal beingindicative of liquid in the appliance interface as such.

In an embodiment, the electronic system further comprises an accessorydevice. According to the embodiment, the electronic device is configuredto, in accordance with determining that liquid is present in theappliance interface, transmit a device signal to the accessory device.

In an embodiment, the accessory device is configured to, in accordancewith receiving the device signal from the electronic device, visualizethe presence of liquid in a user interface of the accessory device, suchas a graphical user interface.

In embodiments, the device signal is a wireless signal transmitted bymeans of a transmission interface of the electronic device, aspreviously disclosed.

As previously discussed, presence of liquid in the appliance interfacecan constitute a risk for the user and/or the equipment (e.g., theelectronic device) or can cause faulty/unreliable (appliance) signals.Thus, it is desired to provide means for communicating such presence ofliquid to the user, such that said user can take remedying actions, suchas to clean the appliance interface. One such way to communicate thepresence of liquid includes notifying the user, e.g. by means of anotification in a graphical user interface of the accessory device, suchas the user's smartphone or -watch, or similar device. Such use of anaccessory device provides for using the electronic device and theassociated electronic system comprising the appliance interface distalthe user's attention, meaning that the user is provided with means forbeing notified of the presence of liquid in the appliance interface,when he/she is not necessarily aware of the electronic device.

Where the electronic device is a monitor device for a medical device,such as a base plate for an ostomy appliance or a wound dressing, andwhere the electronic system is provided in such medical device, liquidis likely to enter the appliance interface, e.g. due to the user notremembering to decouple the electronic device from the applianceinterface in certain situations (e.g. showering or handling theappliance, e.g. in a wet environment, such as in bathroom), or simplynot noticing liquid entering the interface. By transmitting a devicesignal to an accessory device in accordance with determining that liquidis present in the appliance interface, and by visualizing such presencein a user interface of such accessory device, the user is more likely tobecome aware of the presence of liquid and take remedying actions.

In embodiments, the electronic device is configured to, in accordancewith determining that liquid is present in the appliance interface,indicate the presence of liquid by means of a haptic feedback and/or anaudio signal. Thus, in embodiments, the electronic device comprisesmeans for notifying/alerting the user, such as through a haptic feedbackelement and/or a loudspeaker.

In a second aspect of the invention, a method for detecting presence ofliquid in an appliance interface is disclosed. The appliance interfacecomprises at least one primary appliance terminal, a reference applianceterminal, and a dielectric region separating the at least one primaryappliance terminal and the reference appliance terminal.

The method comprises the steps of:

-   -   generating and applying an electrical reference signal to the        reference appliance terminal,    -   detecting an electrical primary signal from the at least one        primary appliance terminal,    -   comparing the primary signal with the reference signal, and    -   determining, in accordance with at least a component of the        primary signal being identical to the reference signal, that        liquid is present in the appliance interface.

The disclosure pertaining to the appliance interface, and embodimentsthereof, according to the first aspect of the invention is consideredapplicable to the method as disclosed herein.

In embodiments, the method is performed by means of/in an externaldevice, such as in an electronic device according to the first aspect ofthe invention. The disclosure pertaining to the electronic device, andembodiments thereof, according to the first aspect of the invention isconsidered applicable to the method as disclosed herein. Thus,embodiments, features, and functionalities disclosed in relation to thefirst aspect of the invention is likewise applicable to the methodaccording to the second aspect of the invention.

The method as disclosed provides a method for detecting presence ofliquid in an appliance interface by means of generating and applying areference signal to a reference appliance terminal of the applianceinterface, detecting a primary signal from at least one primaryappliance terminal of the appliance interface and, in accordance with atleast a component of the primary signal being identical to the referencesignal, determining that liquid is present in the appliance interface.Details on the reference appliance terminal, the at least one primaryappliance interface, the appliance interface in general, and theelectrical signals are disclosed in relation to the first aspect of theinvention.

The step of generating and applying an electrical reference signal tothe reference appliance terminal includes generating such referencesignal in an external device, such as in an electronic device aspreviously disclosed. Further, the step of applying a reference signalincludes establishing an electrical connection between the externaldevice and the appliance interface, e.g. by means of bringing a terminalof the external device into contact with the reference applianceterminal of the appliance interface. For example, the external device,such as the electronic device, can be configured to couple to theappliance interface in such a way that an electrical (e.g., galvanic)connection between the reference device terminal and the referenceappliance terminal is established. In embodiments, the signal isgenerated by means of a driver or the processor and the power unit, suchthat the power unit provides the sufficient current or voltage, and thedriver or processor generates an appropriate reference signal. Inpreferred embodiments, the reference signal has a certaincharacteristic, such as a certain electrical waveform, making it adistinguishable component signal of a possible composite primary signal.

The step of detecting an electrical primary signal from the at least oneprimary appliance terminal includes establishing an electrical (e.g.,galvanic) connection between an external device and the applianceinterface, e.g. by means of bringing a terminal of the external deviceinto contact with the primary appliance terminal of the applianceinterface. Further, by detecting is meant to obtain certain electricalcharacteristics, e.g. variances in voltage, current, resistance, orcapacitance over time. The primary signal can be a composite signal,such that it can comprise one or more component signals from anappliance (e.g., a sensor assembly) comprising the appliance interface,as was discussed in relation to the first aspect of the invention, and acomponent signal pertaining to the reference signal. Liquid in theappliance interface can facilitate the conduction of the referencesignal from the reference terminal to the at least one primary applianceterminal, and thereby, the reference signal becomes a component signalof the primary signal.

The step of comparing the primary signal with the reference signalincludes comparing the two signals and determine their resemblance. Inembodiments, the comparison is performed by an external device, e.g. theelectronic device, comprising processing means for carrying out suchcomparison. In embodiments, the step comprises identifying a componentsignal of the primary signal and comparing such component signal withthe reference signal. If at least a component of the primary signal isidentical to the reference signal (e.g., if at least a component of theprimary signal shares a certain characteristic with the referencesignal), it is indicative of liquid in the appliance interface. Becauseof the presence of (electrically conducting) liquid in the applianceinterface, the primary signal, or a component thereof, is identical tothe reference signal. In other words, since the reference applianceterminal is (structurally and electrically) separated from the primaryappliance terminal by a dielectric region, a resemblance between thereference signal and the primary signal (or component thereof) indicatesa presence of liquid: the liquid bridges from the reference applianceterminal to the primary appliance terminal and thereby facilitates theconduction of the reference signal from the reference appliance terminalto the primary appliance terminal, whereby the primary signal (or acomponent thereof) is identical to the reference signal. In embodiments,resemblance is determined within a certain time period, such as bycomparing the past (trailing) 1 second, or other pre-selected timeperiod, of the primary signal with the past (trailing) 1 second, orother pre-selected time period, of the reference signal.

The step of determining that liquid is present in the applianceinterface is to be considered conditional on the determination that acomponent of the primary signal is identical to the reference signal.

In embodiments, by identical is meant that the (component of the)primary signal and the reference signal share a strong resemblance, suchas at least 80%, or at least 90%, of the measuring points arecoinciding. Alternatively, by identical is meant that a frequency of the(component of the) primary signal is identical to a frequency of thereference signal. In embodiments, by identical is meant that acharacteristic, such as a waveform, of the primary signal (or acomponent thereof) resembles the characteristic, such as the waveform,of the reference signal in a qualitative and/or quantitative manner. Bya qualitative manner is meant that a person skilled in the art (or anartificially intelligence sufficiently trained in the specific use) iscapable of identifying and/or distinguishing the characteristic, such asthe waveform, in a composite signal from noise and/or appliance signals(component signals pertaining to an appliance comprising the applianceinterface). Thus, the reference signal (i.e., the characteristics, suchas the waveform, thereof) is purposively selected to be distinguishable,e.g. by software of the electronic device and/or a skilled person, fromappliance signals contained in the (composite) primary signal. Forexample, the reference signal can be selected by the software of theelectronic device, such as through machine learning software consideringthe appliance signals and, over time, generates a reference signaleasily distinguishable from the appliance signals contained in thecomposite primary signal. Alternatively, the reference signal isselected by the manufacturer of the electronic system, e.g. through themanufacturer's knowledge of the expected appliance signals.

Upon determining that liquid is present in the appliance interface, asystem incorporating the method can be configured to generate anotification or to apply a remedying action. For example, a notificationcan be generated and transmitted to an accessory device, such as asmartphone of a user, the notification prompting such user to clean theinterface. Alternatively, the system incorporating the method can beconfigured to disregard appliance signals until the liquid is removed,i.e. until the appliance interface is dry.

It is foreseen that the method can be incorporated in a variety ofsystems, including an integral (one-part) system and a two-part system.By an integral (one-part) system is meant that an appliance comprisingthe appliance interface comprises means for performing the method,including applying an electrical reference signal, detecting anelectrical primary signal, comparing the signals, and determining thepresence of liquid in the appliance interface. By a two-part system ismeant that such system can be considered a plug-and-socket system,wherein one part (e.g., the plug) is a passive part comprising theappliance interface and a second part (e.g., the socket) is an activepart comprising the means for performing the method (e.g., the secondpart is an external device, such as the electronic device as referred toin the first aspect of the invention). By providing an integral system,the presence of liquid in the appliance interface can be monitoredcontinuously regardless of external device(s) to be coupled to theappliance interface. Thus, an integral system can be provided inproducts/devices such as smartphones, personal devices, or similar,where the presence of liquid in an appliance interface (e.g. a chargingport) can severely affect the functionality or lifetime of suchproducts. A two-part system can be provided as one part (e.g., thepassive part) being disposable, and the second part (e.g., the activepart) being reusable. Thereby is provided a system suitable fordisposable appliances, e.g. medical devices, where certain appliancesare designed to be for single-use only. For example, where the appliancecomprising the appliance interface is a sensor assembly, such sensorassembly can be incorporated in a base plate of an ostomy appliance toprovide such base plate with sensing means, or such sensor assembly canbe incorporated in a wound dressing to provide monitoring of exudateamounts and propagation. In both cases, a base plate and a wounddressing is commonly designed for single-use only, so it is appreciatedthat the sensor assembly and the appliance interface thereof islow-cost, i.e. preferably, the passive part does not comprisecomplicated electronics, e.g. power units and/or processors. Byproviding a two-part system, the relatively more expensive componentsconfigured to carry out the disclosed method, e.g. a power unit and aprocessor, can be incorporated in a separate (reusable) device, such asthe electronic device as disclosed according to the first aspect of theinvention.

In an embodiment, the method is performed in an electronic devicecoupled to the appliance interface.

In embodiments, the electronic device comprises at least one primarydevice terminal connected to the at least one primary appliance terminaland a reference device terminal connected to the reference applianceterminal. By connected is meant that an electrical (e.g., galvanic)connection is established between the at least one primary deviceterminal and the at least one primary appliance terminal and between thereference device terminal and the reference appliance terminal. Therebyis provided a two-part (plug-and socket type) system as discussed above.

Thereby, the electronics, such as a power unit and a processor,configured to carry out the disclosed method can be included in theelectronic device. Thereby, the electronic device can be considered anactive part of the system, and the appliance interface can be consideredthe passive part of the system. In embodiments, the electronic device isreusable, whereas the appliance interface is disposable. Thereby, theappliance interface can be manufactured at a low-cost to provide it as adisposable item, whereas the electronic device can contain therelatively more expensive components.

Embodiments, functionalities, and features of the electronic device,including the at least one primary device terminal and the referencedevice terminal, as disclosed according to the first aspect of theinvention are considered applicable to the present method.

In an embodiment, to generate and apply an electrical reference signalcomprises generating an electrical signal having a first electricalwaveform.

In embodiments, the first electrical waveform is generated by means of apower unit, e.g. coupled to a processor, of an external device, such asof the electronic device. By a first electrical waveform is meant awaveform having certain characteristics, such as a certain shape, suchas a sine waveform, square waveform, triangular waveform or a sawtoothwaveform as previously disclosed in relation to the first aspect of theinvention.

In embodiments, a machine learning functionality of the electronicdevice identifies characteristics of the appliance signal(s) over time,such as to generate/provide a reference signal having a waveform beingdistinguishable from said appliance signal(s). In embodiments, thewaveform is selected by the manufacturer. The first electrical waveformis selected such as to provide a distinguishable component signal, suchthat the reference signal can be identified in the (composite) primarysignal, the identification of the reference signal in the primary signalbeing indicative of liquid in the appliance interface, as previouslydiscussed. Additional details and benefits of providing such a firstelectrical waveform are disclosed in relation to the first aspect of theinvention.

In an embodiment, the appliance interface comprises at least a firstprimary appliance terminal being a terminal of a first electrode and asecond primary appliance terminal being a terminal of a secondelectrode, and the method comprises the additional steps of:

-   -   applying a voltage across the first primary appliance terminal        and the second primary appliance terminal,    -   monitoring the voltage across the first primary appliance        terminal and the second primary appliance terminal, and    -   determining, in accordance with a short-circuit across the first        primary appliance terminal and the second primary appliance        terminal, that liquid is present across the first electrode and        the second electrode.

In embodiments, the first and the second electrode form a sensor for asensor assembly, the sensor assembly here being the appliance comprisingthe appliance interface.

In embodiments, the method is performed in an external device, such asin an electronic device as previously disclosed, or the method isperformed as part of an integral system.

Applying a voltage to the first primary appliance terminal and thesecond primary appliance terminal, e.g. by means of a power unit of theexternal device, consequently applies a voltage across the firstelectrode and the second electrode comprising the first primaryappliance terminal and the second primary appliance terminal,respectively. By monitoring the voltage across the terminals, i.e., overtime, certain aspects of the environment surrounding the electrodes canbe monitored. In particular, a short-circuit can be indicative of liquidforming a bridge across either the terminals or the electrodes connectedthereto. However, by applying different means for detecting liquid inthe appliance interface (by comparing (a component of) the primarysignal with the reference signal, e.g. by comparing their waveforms), adetected short-circuit can be assigned the electrodes, and hence it ispossible to differentiate liquid bridging across electrodes connected tothe terminals from liquid bridging across the terminals as such. Thus,by liquid being present across the first electrode and the secondelectrode is meant that liquid has short-circuited the two electrodes,i.e. liquid forms a (conductive) bridge/path from the first electrode tothe second electrode. It should be noted that the described embodimentof the method pertains to liquid detection, but that the method as suchcan be employed other types of sensors configured to generate a changein voltage based on sensory input (e.g., environmental changes/changesin the surroundings of the sensors).

In embodiments where the electrodes are provided as a sensor of a sensorassembly for a medical device, such as a base plate for an ostomyappliance, the presence of liquid at the electrodes/sensor can beindicative of the presence of output emanating from a stoma. Inembodiments, the electronic device is configured to analyze suchinformation and/or to alert a user.

In an embodiment, the method further comprises, in accordance withdetermining that liquid is present in the appliance interface, the stepsof:

-   -   transmitting a device signal to an accessory device comprising a        graphical user interface, and    -   indicating the presence of liquid in the graphical user        interface.

In embodiments, by indicating is meant to visualize, such as tovisualize a graphical representation of the appliance interface, or suchas to generate a notification, e.g. through a text message or in an app.

By transmitting a device signal to an accessory device in accordancewith determining that liquid is present in the appliance interface, andby visualizing such presence in a user interface of such accessorydevice, the user is more likely to become aware of the presence ofliquid and take remedying actions.

In a third aspect of the invention, a substantially planar applianceinterface is disclosed. The appliance interface comprises at least oneprimary appliance terminal, a reference appliance terminal, and adielectric region separating the at least one primary appliance terminaland the reference appliance terminal. The dielectric region encloseseach of the at least one primary appliance terminals.

Embodiments and related definitions disclosed in relation to theappliance interface of the first and/or the second aspect of theinvention are considered applicable to the third aspect of theinvention.

In embodiments, the appliance interface is substantially planar, suchthat a surface of the appliance interface is substantiallytwo-dimensional. Thus, the at least one primary appliance terminal, thereference appliance terminal and the dielectric region may be arrangedin an appliance interface plane, such that the dielectric regionencloses, in the appliance interface plane, each of the at least oneprimary appliance terminals.

In embodiments, the at least one primary appliance terminal and thereference appliance terminal are provided on a non-conductive substrateand separated from each other, e.g. separated by the dielectric region.In embodiments, the at least one primary appliance terminal iselectrically connected to an appliance, such as to at least oneelectrode of such an appliance. In embodiments, the substrate isstretchable. In embodiments, the substrate is polymeric.

According to the third aspect of the invention, the dielectric regionencloses each of the one or more primary appliance terminals. Thus, atleast one dielectric region is provided, such as a dielectric region foreach of the primary appliance terminals provided. By enclosing is meantthat the dielectric region surrounds, in the plane, each of the one ormore primary appliance terminals when seen in a direction normal to theappliance interface, i.e. a top view of the appliance interface.

In embodiments, the dielectric region extends radially away, in theplane, from an edge of the at least one primary appliance terminal by atleast 0.1 mm, such as 0.1 mm, or 0.2 mm, or 0.3 mm, or 0.4 mm, or 0.4mm, or 0.6 mm, or 0.7 mm, or 0.8 mm, or 0.9 mm, or 1 mm. In embodiments,the dielectric region extends radially away, in the plane, from an edgeof the at least one primary appliance terminal by at least 1 mm. Inembodiments, the dielectric region extends radially away, in the plane,from an edge of the at least one primary appliance terminal by maximally5 mm. By providing a maximum distance is facilitated that liquid presentin the appliance interface is likely to bridge across the dielectricregion to provide a conduction of an electrical signal from thereference appliance terminal to the primary appliance terminal.

In embodiments, an outer periphery of the dielectric region is adjacent,in the plane, to the reference appliance terminal, such as an enclosingportion of the reference appliance terminal. Thereby, the referenceappliance terminal generally covers a substantial (e.g. more than 25%,or more than 50%) surface area of the appliance interface. In otherwords, when providing a substantially planar appliance interface andwhen seen from a direction normal to said interface (top-view), adielectric region enclose/surround each of the primary applianceterminal(s), such that said dielectric region separates the at least oneprimary appliance terminal and the reference appliance terminal. Thus,the (two-dimensional) shape of the reference appliance terminal does notnecessarily correspond to the (two-dimensional) shape of the primaryappliance terminal. Rather, the reference appliance terminal cancomprise a planar contact pad for contacting a corresponding referencedevice terminal of an electronic device and a planar enclosing portionat least partly enclosing the at least one primary appliance terminal inthe plane—separated by a planar dielectric region.

In a fourth aspect of the invention, a medical device comprising theelectronic system of the first aspect of the invention is disclosed.

By comprising the electronic system of the first aspect of the inventionis meant that the medical device comprises an appliance interface and anelectronic device couplable to the appliance interface. In embodiments,the appliance interface is an appliance interface of an applianceembedded/incorporated in the medical device. A medical device comprisingan electronic system as previously disclosed provides for a medicaldevice suitable for implementing sensors or similar appliances. Forexample, the appliance can be embedded or incorporated in the medicaldevice to provide said medical device with the functionalities of theappliance. In embodiments, the appliance is a sensor assembly, and theappliance interface is an appliance interface of such sensor assembly.

Certain medical devices are likely to be exposed to body fluids and/orwater or liquids in general. Due to the risk of exposure to body fluidsand/or water, it is desired to provide a medical device having anincorporated appliance with the functionalities of the electronic systemaccording to the above aspects of the invention, namely the ability todetect presence of liquid in the appliance interface. Thereby, a user ofthe medical devices can be notified of such presence of liquid.

In an embodiment, the medical device comprises an ostomy appliance.

By an ostomy appliance is meant at least an appliance comprising a baseplate for attachment to a peristomal skin surface of a user having anostomy by means of an adhesive surface, and optionally a collection bagattached/attachable to the base plate for the collection of outputemanating from such ostomy. Thus, according to the embodiment, theostomy appliance comprises the electronic system according to previousdisclosure. In embodiments, the appliance interface is an applianceinterface of a sensor assembly for incorporation and/or attachment tothe base plate and/or collection bag for sensing various parameterspertaining to the operation of the ostomy appliance, e.g. for alertingthe user of an imminent risk of leakage (output escaping the ostomyappliance and becoming a burden to the user).

In embodiments, the sensor assembly is configured for detecting moisturein the adhesive of the base plate and/or for detecting presence ofliquid in the interface between the adhesive surface and the peristomalskin surface. In such uses, it is desired to provide the sensor assemblyand the appliance interface as a disposable item, such that the user candispose of the base plate after use without detaching the sensorassembly. Instead, the electronic device can be provided as a reusableitem, such that the sensor assembly and the appliance interface can beof relative low cost, whereas the electronic device can compriserelative more expensive electronics, such as the electronics forcontrolling the appliance. In embodiments, the sensor assembly isprovided in a sensor patch for attachment to the proximal adhesivesurface of a base plate.

Since an ostomy appliance is configured to be worn at any given time,such as during exercise or showering, the risk of liquid entering theappliance interface is finite. By providing the sensor assembly embeddedin the base plate with an electronic system as disclosed, presence ofliquid in the appliance interface can be detected. In embodiments, thepresence of liquid in the appliance interface can be detected withoutcompromising the functionalities of the sensor assembly.

In an embodiment, the medical device comprises a wound dressing.

By a wound dressing is meant a dressing for covering and/or treating awound. In embodiments, the wound dressing comprises an absorbent corelayer for absorbing exudates from the wound. In embodiments, the wounddressing further comprises a first adhesive layer with a proximalsurface for attachment of the wound dressing to the skin surface of auser, and a top-film covering the absorbent core layer. In embodiments,the absorbent core layer comprises a proximal surface, i.e. theskin-facing surface when the user wears the wound dressing, and a distalsurface, i.e. the surface facing away from the skin surface. Inembodiments, the top-film is arranged on the distal side of theabsorbent core layer and the first adhesive layer is arranged on theproximal side of the absorbent core layer.

In embodiments, a sensor assembly—the appliance within the presentcontext—is arranged on the proximal side of the absorbent core layer. Inembodiments, the sensor assembly is arranged on the distal side of theabsorbent core layer. Providing a wound dressing with a sensor assemblyprovides for monitoring such wound dressing, such as for monitoringexudate rate, amounts, and patterns. The sensor assembly comprises theappliance interface as disclosed according to aspects of the invention.Thus, the electronic system can be provided as part of a wound dressing,such that the appliance interface and the appliance (sensor assembly)thereof is provided in the (disposable) wound dressing, whereas theelectronic device is provided as a reusable device couplable to thewound dressing to provide means for monitoring said wound dressing.

In an embodiment, the medical device comprises a urinary catheter. Inembodiments, the urinary catheter is an intermittent urinary catheter.

Providing a urinary catheter with an appliance, such as a sensorassembly for sensing certain characteristics of the (use of the)catheter, may require an external device, such as an electronic deviceaccording to aspects of the invention, to be couplable to an applianceinterface thereof, such as to provide the appliance along with thecatheter as a disposable item. When using a urinary catheter, exposureto body fluids is a factor to consider, since such body fluidspotentially affect signals pertaining to the appliance. Thus, byproviding the urinary catheter with an electronic system according toaspects of the invention, means for detecting liquid (including bodyfluids) in an appliance interface of the appliance is provided.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an electronic system 1 comprising an electronicdevice 200 and an appliance interface 100 according to an embodiment ofthe invention. The appliance interface 100 comprises a primary applianceterminal 101, a reference appliance terminal 110 (hatched for increasedintelligibility), and a dielectric region 120 separating the primaryappliance terminal 101 and the reference appliance terminal 110. In theillustrated embodiment, the dielectric region 120 is further a substratefor the terminals 101,110. Because of the dielectric region 120,electricity/electrical signals cannot be conducted between the referenceappliance terminal 110 and the primary appliance terminal 101 in a drystate of the appliance interface 100. The primary appliance terminal 101and the reference appliance terminal 110 are conductive, such as made ofsilver or carbon, such as silver provided, e.g. printed, on thedielectric substrate. The dielectric substrate can be (printable)isobornyl acrylate, but can be anything electrically insulating,including polymers and ceramic materials. By providing printablematerials, the entire appliance interface 100, including the terminals101,110 and the dielectric region 120, can be printed, providing for afast and cheap production process. In preferred embodiments, thedielectric substrate is stretchable, such as to provide a flexibleappliance interface.

The primary appliance terminal 101 is a terminal of an appliance 2 (suchas a component, device, or network), such as an appliance 2 comprising asensor 3. Thereby, data, such as changes in an electricalparameter/quantity, can be extracted from the appliance 2 by means ofthe electronic device 200 through the primary appliance terminal 101 ofthe appliance interface 100. Thus, the sensor 3 is electricallyconnected to the primary appliance terminal 101 through an electrode 3′.

The reference appliance terminal 110 is not electrically connected toany part of the appliance 2. Thus, the reference appliance terminal 110is a conductive terminal solely provided in/on the appliance interface100.

The electronic device 200 comprises a corresponding device interface200′ comprising a corresponding primary device terminal 201 and acorresponding reference device terminal 210.

The electronic device 200 and the appliance interface 100 are configuredto engage in such a manner that an electrical (galvanic) connection canbe established across the corresponding terminals. According to theillustrated embodiment, the terminals are engageable, whereas inalternative embodiments, the terminals are substantially planar, suchthat an electrical connection is established by the terminals merelytouching each other. According to the illustrated embodiments, theappliance interface 100 resembles a male plug, and the device interface200′ resembles a female socket. In alternative embodiments, theappliance interface 100 resembles a female socket, and the deviceinterface 200′ resembles a male plug. In further alternativeembodiments, the device interface 200′ is configured to receive theappliance interface 100 in a slit, such that the appliance interface issubstantially planar and can be inserted into the slit of the electronicdevice 200. Further engagement options between the appliance interface100 and the electronic device 200 are foreseen within the scope of theinvention, and the illustrated and described embodiments are notintended to limit the claimed invention.

The electronic device 200 comprises a housing 202, a processor 203, apower unit 204 and a circuitry 205. Optionally, the electronic device200 further comprises a memory (not shown). The power unit 204 canconfigured to apply a voltage across two or more terminals or togenerate an electrical signal. The power unit 204 comprises a battery.The battery can be charged through the device interface 200′, such as byconnecting the electronic device 200 to a charging unit (not shown)having dimensions corresponding to the appliance interface 100.

The electronic device 200 is configured to apply an electrical referencesignal to the reference appliance terminal 110 through the referencedevice terminal 210, and to detect an electrical primary signal from theprimary appliance terminal 101 through the primary device terminal 201.The electronic device 200 is configured to, e.g. by means of theprocessor 203, compare the primary signal with the reference signal,and, in accordance with at least a component of the primary signal beingidentical to the reference signal, determine that liquid is present inthe appliance interface 100, i.e. in the interface between the applianceinterface 100 and the electronic device 200 when these are coupled. Byat least a component is meant that the primary signal can be a compositesignal comprising one or more component signals (appliance signals) fromthe appliance 2, and a component signal from the reference applianceterminal 110, i.e. the component carrying the reference signal. Thus,presence of liquid in the appliance interface 100 can be detected whilereceiving appliance signals from the appliance 2. In other words, inembodiments, the electronic device 200 is configured to identify acomponent of the primary signal, and, in accordance with such componentbeing identical to the reference signal, determine that liquid ispresent in the appliance interface 100.

FIG. 2A illustrates a top view of the appliance interface 100 comprisingthe primary appliance terminal 101 and the reference appliance terminal110. A dielectric region 120 separates the primary appliance terminal101 from the reference appliance terminal 110. The appliance interface100 can be substantially planar, such that the terminals are planarcontact pads configured to touch/engage with corresponding contact padsof an electronic device. The primary appliance terminal 101 is inelectrical communication with (is a terminal of) an (electrode of an)appliance (not shown), whereas the reference appliance terminal 110 iselectrically isolated from any other electrically conductive part.

FIG. 2B illustrates the appliance interface 100 of FIG. 2A, where liquid10 forms a (conductive) bridge between the reference appliance terminal110 and the primary appliance terminal 101. Thus, the liquid 10 extendsacross the dielectric region 120 and hence forms a path for conductingan electrical signal (e.g., the reference signal). When an electronicdevice 200 configured to apply a reference signal to the referenceappliance terminal 110 and to detect a primary signal from the primaryappliance terminal 101 is coupled to the appliance interface 100, thereference signal conducts through the liquid 10, whereby (at least acomponent of) the detected primary signal equals the reference signal,i.e. the signals or at least components thereof are identical. Thus, adetermination of at least a component of the primary signal beingidentical to the reference signal is indicative of the presence ofliquid 10 in the appliance interface 100. Upon such determination, theelectronic device can be configured to enter a state of safety, wherebydamage to sensitive electronics, such as the battery and/or power unit,is avoided. Alternatively, or additionally, upon such determination ofthe presence of liquid, the electronic device can be configured to alerta user and/or to generate and transmit a device signal to an accessorydevice, such as a smartphone or smartwatch, indicating the presence ofliquid to the user. Further, upon such determination, the electronicdevice can be configured to disregard appliance signal(s) pertaining tothe appliance connected to the primary appliance terminal 101, sincesuch appliance signal(s) can be disrupted and/or faulty because of thepresence of the liquid in the appliance interface 100. In embodimentswhere the appliance interface 100 comprises a plurality of primaryappliance terminals, the electronic device can be configured todisregard the appliance signal(s) pertaining to the specific primaryappliance terminal in contact with liquid, or to disregard the appliancesignals pertaining to all primary appliance terminals, such as until theuser has removed the liquid.

FIG. 3A illustrates an exemplary cross-sectional view of an applianceinterface 100 of a sensor 3, i.e., the sensor 3 is the appliance withinthe present context. The primary appliance terminal 101 is electricallyconnected to the sensor through the electrode 3′. The electrode 3′ assuch may form part of the sensor 3. Arrows indicate the transfer ofelectrical signals. It is appreciated that a more complex situation mayarise, such as where the appliance interface comprises multipleappliance terminals or where varying signals are generated, and as such,the indicated transfer of electrical signals are included for schematicand illustrative purposes only. By means of an electronic device (notshown) coupled to the appliance interface 100, a reference signal E1 isapplied to the reference appliance terminal 110. Likewise, a primarysignal E2 is detected by the electronic device at the primary applianceterminal 101. The primary signal E2 can be a component signal, and inthe illustrated case, the primary signal E2 comprises a single componentsignal: the appliance signal A1.

For example, the appliance signal A1 carries information pertaining tothe sensor 3.

FIG. 3B illustrates the exemplary cross-sectional view of FIG. 3A in acase where liquid 10 is present on the surface of the applianceinterface 100. The liquid 10 forms a conductive path between thereference appliance terminal 110 and the primary appliance terminal 101.Again, arrows indicate the transfer of electrical signals. Due to thepresence of liquid 10, the reference signal E1 is conducted through theliquid 10, such that the primary signal E2 detected at the primaryappliance terminal 101 is a composite signal comprising two componentsignals, one being the appliance signal A1, and one being the referencesignal E1, such that E2=A1+E1. The electronic device coupled to theappliance interface 100 is configured to compare the primary signal E2with the reference signal E1. Because a component of the primary signalE2 pertains to the reference signal E1, the electronic device isconfigured to determine that liquid 10 is present in the applianceinterface 100.

FIGS. 4A and 4B illustrate a top view of an appliance interface 100according to an embodiment of the invention. The appliance interface 100may be substantially planar and comprises, as in FIGS. 2A-2B, a primaryappliance terminal 101, a reference appliance terminal 110, and adielectric region 120 separating the terminals 101,110. The referenceappliance terminal 110 comprises a contact pad 111 and an enclosingportion 112. The enclosing portion 112 comprises a first leg 112 a and asecond leg 112 b partly enclosing the primary appliance terminal 101 inthe plane of the appliance interface 100. The enclosing portion 112 canbe considered an extension of the reference appliance terminal 110, suchthat liquid 10 can be detected whenever a bridge thereof forms betweenany part (contact pad 111 and/or enclosing portion 112) of the referenceappliance terminal 110 and the primary appliance terminal 101—see FIG.4B. The legs 112 a,112 b of the enclosing portion 112 extends in thesame plane as the appliance interface 100, such that by enclosing ismeant that the enclosing portion 112 surrounds at least partly theprimary appliance terminal 101 in said plane. The enclosing portion 112increases the likelihood that presence of liquid 10 in the applianceinterface 100 is detected according to embodiments of the invention.

FIGS. 5A and 5B illustrate a top view of an appliance interface 100according to an alternative embodiment of the invention. Here, thedielectric region 120 (dotted) encloses/surrounds the (immediatevicinity of) the primary appliance terminal 101. Thus, the dielectricregion 120 extends radially away from a periphery/edge of the primaryappliance terminal, e.g. by a distance between 0.1 mm and 2 mm, e.g. avarying distance. The dielectric region 120 electrically insulates theprimary appliance terminal 101 from the reference appliance terminal110. Here, the reference appliance terminal 110 comprises anelectrically conductive contact pad 111 and an electrically conductivecoherent enclosing portion 112′. Different from the embodiment of FIGS.4A-4B, the enclosing portion 112′ is here a coherent/integral bodycovering a substantial part (e.g., >50%) of the surface area of theappliance interface 100. Thus, a substantial part of the surface of theappliance interface 100 is conductive and essentially constitutes thereference appliance terminal to which a reference signal can be applied.However, for practical reasons, a designated area, the contact pad 111,is configured to receive a corresponding reference device terminal ofthe electronic device. For example, the contact pad 111 can bereinforced to withstand wear and tear resulting from a prolongedgalvanic contact with the corresponding reference device terminal.Nevertheless, the contact pad 111 is in electricalcommunication/integral with the enclosing portion 112′.

FIG. 5B illustrates the situation where liquid 10 forms a bridge acrossthe dielectric region 120 separating the primary appliance terminal 101and the (enclosing portion 112′ of the) reference appliance terminal110. Here, an electronic device (not shown) coupled to the applianceinterface 100 is capable of detecting the presence of liquid 10, sincean applied reference signal conducts from the contact pad 111, into theenclosing portion 112′, through the liquid 10, and becomes a componentsignal of the primary signal, as was elaborated in relation to FIG. 3B.

FIGS. 6A-6D illustrate four exemplary electrical signals having acertain waveform. According to an aspect of the invention, it is desiredto provide a reference signal being distinguishable from appliancesignal(s) (in FIGS. 3A-3B referred to as A1) pertaining to theappliance, since such appliance signals are contained in the primarysignal—potentially along with the reference signal. In other words, theprimary signal can be a composite signal comprising both the appliancesignals and the reference signal once said reference signal has beenconducted through liquid in the appliance interface.

In particular, since appliance signals can vary according tosurroundings (e.g., where the appliance is a sensor) and potentiallycomprise a degree of noise, it is desired to apply a reference signal tothe reference appliance terminal being distinguishable/unique from suchexpected appliance signals. In embodiments, the electronic device isconfigured to receive a composite primary signal, i.e. an electricalsignal comprising a (component) appliance signal pertaining to theappliance (e.g., sensor) to which the primary appliance terminal iscoupled, and—upon presence of liquid in the appliance interface—acomponent signal pertaining to the reference signal. Thus, when liquidis present in the appliance interface, the electronic device essentiallyreceives a mix/composite of electrical signals in the primary signal,the composite comprising the component signal pertaining to theappliance and the component signal pertaining to the reference signalapplied to the reference appliance terminal. When the reference signalis distinguishable from the expected appliance signals, it is possibleto identify/distinguish the component signal pertaining to the referencesignal from the appliance signals.

One way of providing a distinguishable reference signal is to generate areference signal having a certain electrical waveform, such as aperiodic waveform, which is not expected from the appliance signals. Forexample, the processor and/or power unit of the electronic device can beconfigured to generate such certain electrical waveform. For example,the waveform of the reference signal varies (periodically) as voltage V,current I, magnetic field B, or electrical field E, as a function oftime t (see FIG. 6D). In preferred embodiments, the voltage V or currentI varies as a function of time t.

FIG. 6A illustrates a sine wave, where the amplitude of the waveformfollows a trigonometric sine function with respect to time. FIG. 6Billustrates a square wave of constant period. In alternativeembodiments, the period varies, such as to form a rectangular wave. FIG.6C illustrates a triangular wave. FIG. 6D illustrates a sawtooth wave.The waveforms are included for illustrative purposes only, and theamplitude, wavelength, and/or phase are not necessarily to scale.Alternative waveforms are foreseen within the scope of the invention, asthe waveform is merely to be selected to make it distinguishable fromthe expected appliance signals from the appliance. Thus, in embodiments,the waveform is selected such that it is distinguishable/different from(expected) appliance signals from the appliance. Four such potentiallydistinguishable waveforms may include a sine wave, a square wave, atriangular wave and a sawtooth wave as illustrated.

FIG. 7 illustrates a top view of an appliance interface 100 comprisingseven primary appliance terminals 101 and a reference appliance terminal110 according to an embodiment of the invention. Providing a pluralityof primary appliance terminals 101 allows for controlling a morecomplicated appliance, i.e. an appliance electrically connected throughelectrodes 2′ to the primary appliance terminals 101. As previouslydescribed, the reference appliance terminal 110 is electrically isolatedfrom the appliance and the electrodes 2′ connecting said appliance tothe primary appliance terminals 101. The reference appliance terminal110 of the illustrated embodiment comprises a contact pad 111 and anenclosing portion 112, as previously described. The enclosing portion112 partly encloses/surrounds, in the plane of the appliance interface100, the plurality of primary appliance terminals 101 by means of aplurality of legs extending into the gaps between said primary applianceterminals 101. The arrangement and number of legs can vary, such asdepending on the arrangement of primary appliance terminals 101 and/orthe desired sensitivity towards detecting presence of liquid. Each ofthe plurality of primary appliance terminals 101 and the contact pad 111and the enclosing portion 112 are separated by a dielectric region 120,such that an electrical signal can only be conducted between thereference appliance terminal 110 (or the enclosing portion 112 thereof)and one or more of the primary appliance terminals 101 upon presence ofliquid in the appliance interface 100.

FIG. 8A illustrates an appliance interface 100 comprising seven primaryappliance terminals 101 and a reference appliance terminal 110 accordingto an embodiment of the invention. The appliance interface 100 differsfrom the one illustrated in FIG. 7 in that the dielectric region 120(dotted) surrounds the (immediate vicinity of) the primary applianceterminal 101 only (see also FIGS. 5A-5B). Further, the referenceappliance terminal 110 comprises a contact pad 111 and a coherentenclosing portion 112′. Contrary to the embodiment of FIG. 7, theenclosing portion 112′ is a coherent/integral portion covering asubstantial part (e.g., >50%) of the surface of the appliance interface100. Thus, a substantial part of the surface of the appliance interface100 is conductive and essentially constitutes the reference applianceterminal 110 to which a reference signal can be applied by means of anelectronic device coupled to the appliance interface 100. However, forpractical reasons, a designated area, the contact pad 111, is configuredto electrically connect to a corresponding reference device terminal ofthe electronic device. For example, the contact pad 111 can bereinforced to withstand wear and tear from the contact with thecorresponding reference device terminal but is nevertheless inelectrical communication/integral with the enclosing portion 112′. Theseven primary appliance terminals 101 are coupled to an appliancethrough the electrodes 2′ (the exact arrangement of electrodes 2′ mayvary but are in general isolated from the reference appliance terminal).

FIG. 8B illustrates a cross-sectional view of the appliance interface ofFIG. 8A taken along the line A-A in FIG. 8A. The cross-sectional viewillustrates one way of realising the appliance interface 100 of FIG. 8A,but alternative builds of the appliance interface 100 of FIG. 8A areforeseen within the scope of the invention. The cross-sectional viewillustrates three primary appliance terminals 101, each connected to anappliance through the electrodes 2′. A dielectric layer forming thedielectric region 120 surrounding each of the primary applianceterminals 101 is arranged (e.g. deposited or printed) between saidterminals, and finally, a conductive layer forming the referenceappliance terminal 110 (and the enclosing portion 112′ thereof) isarranged (e.g. deposited or printed) on top of the dielectric layer. Acertain region of the reference appliance terminal 110 constitutes thecontact pad 111, whereas the remaining region constitutes the enclosingportion 112′. In embodiments, the dielectric layer forming thedielectric region 120 extends underneath, i.e. supports, the primaryappliance terminals 101, such that in alternative ways of realising theappliance interface 100, the dielectric layer 120 is provided as asubstrate, and the primary appliance terminals 101 are arranged (e.g.deposited or printed) on top of the dielectric layer 120. Finally, thereference appliance terminal 110 (or enclosing portion 112′ thereof) isarranged (e.g. deposited or printed) in between the reference applianceterminals 110, leaving a dielectric region 120 about each of the primaryappliance terminals 101. The dimensions are highly exaggerated forillustrative purposes. A thickness of the conductive primary/referenceappliance terminals 101,110 may be within the range of 1 μm and 50 μm,such as between 2 μm and 20 μm, such as between 4 μm and 10 μm.

FIGS. 9A and 9B illustrate the embodiment of the appliance interface 100of FIGS. 8A-8B, wherein a liquid 10 is present. The liquid 10extends/forms a bridge from a primary appliance terminal 101 to theenclosing portion 112′ of the reference appliance terminal 110. Thereby,a reference signal E1 applied to the reference appliance terminal 110,e.g. through the contact pad 111 and therefrom into the enclosingportion 112′, is conducted through the liquid 10 and is detectable inthe primary signal E2 at the primary appliance terminal 101 by means ofan electronic device coupled to the interface, as previously described.The primary signal E2 can be a composite signal comprising a (component)appliance signal A1, such that the primary signal E2=A1+E1. Since theelectronic device is configured to compare the primary signal E2 withthe reference signal E1 and determine that at least a component (thecomponent pertaining to the reference signal E1) of said primary signalE2 is identical to the reference signal E1, a presence of liquid 10 inthe appliance interface 100 can be determined.

FIG. 10 illustrates a perspective schematic view of an electronic system1 according to an embodiment of the invention. The electronic system 1comprises an electronic device 200 and a planar appliance interface 100couplable to the electronic device 200. The appliance interface 100comprises the features as previously disclosed; (here, five) primaryappliance terminals 101, a reference appliance terminal 110 comprising acontact pad 111 and an enclosing portion 112′ enclosing/surrounding theprimary appliance terminals 101, and (here, five) dielectric regions 120(dotted) separating each of the primary appliance terminals 101 from the(enclosing portion 112′ of the) reference appliance terminal 110. Theappliance interface 100 is an appliance interface of an appliance 2, andthe primary appliance terminals 101 are individually electricallyconnected to an electrode 2′ of the appliance 2.

The electronic device 200 comprises a corresponding device interface200′. The device interface 200′ comprises primary device terminals 201having a size and shape corresponding to the primary appliance terminals101 and a reference device terminal 210 having a size and shapecorresponding to the reference appliance terminal 210. The terminals201,210 of the device interface 200′ are electrically insulated by adevice dielectric region 220.

The electronic device 200 comprises electronics, such as a processor, apower unit and optionally a wireless transceiver configured to transmitdevice signals 402 wirelessly to an accessory device, such as asmartphone 400 comprising a graphical user interface 401. For example,device signals 402 comprises data pertaining to the appliance 2 or to adetermined presence of liquid in the appliance interface 100. Thereby, auser of the electronic system 1 can easily access data through thegraphical user interface 401 and act according to generatedinstructions, such as instructions to clean/dry the appliance interface100.

FIG. 11 illustrates an exemplary sensor assembly 300 (appliance)comprising the appliance interface 100 as previously disclosed.

The sensor assembly 300 can be provided in a variety of devices orenvironments, wherein sensing is desired. For example, the sensorassembly 300 can be provided in a medical device, such as an ostomyappliance or a wound dressing.

For example, the sensor assembly 300 can be provided as part of a baseplate 310 of an ostomy appliance, or a sensor patch attachable to a baseplate of an ostomy appliance. For example, the sensor assembly 300 canbe arranged to facilitate detection of liquid propagating in theinterface between an adhesive proximal surface of the base plate 310 andthe peristomal skin surface of a user, in order to provide a warningthat a leakage of stomal output is imminent.

According to the illustrated embodiment, the sensor assembly 300comprises three sensors 301,302,303 each comprising two electrodes. Thethree sensors 301,302,303 are concentric about a stomal opening 311 ofthe base plate 310. The innermost sensors 301,303 each cover anon-overlapping angle space of 180° about the stomal opening 311. Thedeashed electrode represents a common ground electrode, such that threesensors 301,302,303 may be formed from four electrodes as illustrated.Different layouts of electrodes may be provided for forming furtherand/or different sensors, within departing from the scope of theinvention.

The electrodes of the sensors 301,302,303 extend into the (planar)appliance interface 100, such that each electrode terminates in aprimary appliance terminal 101. An electronic device 200 as previouslydisclosed is couplable to the appliance interface 100 through the deviceinterface 200′, such as to provide means for operating the sensors301,302,303, such as to detect liquid propagating in the interfacebetween the adhesive proximal surface of the base plate 310 and theperistomal skin surface of the user and/or to detect moisture absorptionin the adhesive material of the base plate. Thus, the electronic device200 can be coupled to the sensor assembly 300 in order to access orgather data from the sensors 301,302,303. For example, the electronicdevice 200 can be configured to apply a voltage across two electrodesforming a sensor and monitor changes in resistance across the twoelectrodes, a change in resistance being indicative of moistureabsorption in the adhesive base plate and/or presence of liquid in theinterface between the adhesive proximal surface of the base plate 310and the peristomal skin surface of the user. Due to an ostomy appliancebeing a medical device worn continuously by the user, such as duringshowering or exercise, an undesired presence of liquid in the applianceinterface 100 is likely. However, such undesired presence of aconducting liquid in the appliance interface 100 can causemalfunctioning of the electronic device 200 and/or cause faulty signalsfrom the sensor assembly 300. Thus, it is desired to provide means fordetecting presence of such liquid in the appliance interface 100. Suchmeans are provided according to previously disclosed embodiments of theelectronic system according to aspects of the invention disclosedherein. According to the embodiment of FIG. 11, the appliance interface100 comprises four primary appliance terminals 101, each being connectedto one of the four electrodes forming the three sensors 301,302,303 ofthe sensor assembly 300. Each primary appliance terminal 101 issurrounded by a dielectric region 120 separating the primary applianceterminals 101 from the enclosing portion 112′ and the contact pad 111constituting/forming the reference appliance terminal 110. Theelectrodes are included for illustrative purposes, but it is emphasizedthat these are isolated from the reference appliance terminal 110,including the enclosing portion 112′ thereof. Presence of liquid in theappliance interface 100 is detected by means of the electronic device200 couplable to the appliance interface 100, as previously described indetail.

When using the appliance interface 100 in a sensor assembly 300 for anostomy appliance, it is desired to provide the sensor assembly 300,including the appliance interface 100, as a disposable item. Thus, theappliance interface 100 is designed to provide a low manufacturing cost,whereas the electronic device 200 comprises the required electronicsneeded to operate the appliance (sensor assembly 300) and the applianceinterface, such that said electronic device 200 can be reusable and canbe coupled to a new appliance interface after use.

FIG. 12 illustrates a close-up top view of a (planar) applianceinterface 100 according to an embodiment of the invention. The applianceinterface 100 of FIG. 12 illustrates a primary appliance terminal 101, adielectric region 120 enclosing/surrounding the primary applianceterminal 101 and a fragment of the enclosing portion 112′ (dashed) ofthe reference appliance terminal. The primary appliance terminal 101 isshaped as a contact pad having certain dimensions. A maximum dimension Mis illustrated. In embodiments, the maximum dimension M is between 0.5mm and 5 mm, or maximally 10 mm. The primary appliance terminal 101comprises a periphery 102 defining its shape/extent in a two-dimensionalgeometrical plane. The dielectric region 120 is arranged about theentire periphery 102, such that said dielectric region 120 encloses theprimary appliance terminal 101. The dielectric region 120 extends adistance N radially away from the (periphery 102 of) primary applianceterminal 101. For example, the dielectric region 120 extends between 0.1mm and 2 mm, such as 1 mm radially away from the periphery 102 of theprimary appliance terminal 101. The dielectric region 120 separates andinsulates the primary appliance terminal 101 from the (enclosing portion112′ of the) reference appliance terminal. Thus, the dielectric region120 comprises an inner periphery 121 arranged adjacent to the periphery102 of the primary appliance terminal 101, and an outer periphery 122arranged adjacent to the enclosing portion 112′ of the referenceappliance terminal.

Although particular features have been shown and described, it will beunderstood that they are not intended to limit the claimed invention,and it will be made obvious to those skilled in the art that variouschanges and modifications may be made without departing from the spiritand scope of the claimed invention. The specification and drawings are,accordingly, to be regarded in an illustrative rather than restrictivesense. The claimed invention is intended to cover all alternatives,modifications, and equivalents.

1-26. (canceled)
 27. An electronic system for detecting presence ofliquid in an appliance interface, the system comprising: an applianceinterface comprising a first primary appliance terminal, a referenceappliance terminal, and a dielectric region separating the first primaryappliance terminal and the reference appliance terminal; and anelectronic device couplable to the appliance interface, the electronicdevice comprising: a first primary device terminal configured to connectto the first primary appliance terminal, and a reference device terminalconfigured to connect to the reference appliance terminal, wherein theelectronic device is configured to generate and apply an electricalreference signal to the reference appliance terminal, detect anelectrical primary signal from the first primary appliance terminal,compare the primary signal with the reference signal, and in accordancewith at least a component of the primary signal being identical to thereference signal, determine that liquid is present in the applianceinterface.
 28. The electronic system according to claim 27, wherein thereference signal has a first electrical waveform.
 29. The electronicsystem according to claim 28, wherein the first electrical waveform isselected from a sine waveform, a square waveform, a rectangularwaveform, a triangular waveform, and a saw-toothed waveform.
 30. Theelectronic system according to claim 27, wherein the appliance interfaceis substantially planar.
 31. The electronic system according to claim27, wherein the reference appliance terminal comprises a contact pad andan enclosing portion, the enclosing portion at least partly enclosingthe first primary appliance terminal.
 32. The electronic systemaccording to claim 31, wherein the reference device terminal isconfigured to connect to the contact pad of the reference applianceterminal.
 33. The electronic system according to claim 27, wherein thefirst primary appliance terminal is a terminal of an electrode of asensor.
 34. The electronic system according to claim 27, wherein theappliance interface comprises a second primary appliance terminal andwherein the electronic device comprises a second primary deviceterminal.
 35. The electronic system according to claim 34, wherein theelectronic system further comprises an appliance connected to theappliance interface, and wherein the first primary appliance terminal isa terminal of a first electrode of the appliance, and the second primaryappliance terminal is a terminal of a second electrode of the appliance.36. The electronic system according to claim 34, wherein the electronicdevice is configured to apply a voltage across the first primaryappliance terminal and the second primary appliance terminal.
 37. Theelectronic system according to claim 36, wherein the electronic deviceis configured to detect a short-circuit across the first primaryappliance terminal and the second primary appliance terminal.
 38. Theelectronic system according to claim 37, wherein the electronic systemfurther comprises an appliance connected to the appliance interface, andwherein the first primary appliance terminal is a terminal of a firstelectrode of the appliance, and the second primary appliance terminal isa terminal of a second electrode of the appliance, and wherein theelectronic device is configured to, in accordance with a detection of ashort-circuit across the first primary appliance terminal and the secondprimary appliance terminal, determine that liquid is present in theappliance.
 39. The electronic system according to claim 27, wherein theelectronic system further comprises an accessory device, and wherein theelectronic device is configured to, in accordance with determining thatliquid is present in the appliance interface, transmit a device signalto the accessory device.
 40. The electronic system according to claim39, wherein the accessory device is configured to, in accordance withreceiving the device signal from the electronic device, visualize thepresence of liquid in a user interface of the accessory device.
 41. Theelectronic system according to claim 27, wherein the appliance interfaceis disposable, and wherein the electronic device is reusable.
 42. Theelectronic system according to claim 27, wherein the appliance interfaceis arranged on a stretchable substrate.
 43. A method for detectingpresence of liquid in an appliance interface comprising a first primaryappliance terminal, a reference appliance terminal, and a dielectricregion separating the first primary appliance terminal and the referenceappliance terminal, the method comprising the steps of: generating andapplying an electrical reference signal to the reference applianceterminal, detecting an electrical primary signal from the first primaryappliance terminal, comparing the primary signal with the referencesignal, and determining, in accordance with at least a component of theprimary signal being identical to the reference signal, that liquid ispresent in the appliance interface.
 44. The method according to claim43, wherein the method is performed in an electronic device coupled tothe appliance interface.
 45. The method according to claim 43, whereingenerating and applying the electrical reference signal comprisesgenerating an electrical signal having a first electrical waveform. 46.The method according to claim 43, wherein the appliance interfacecomprises the first primary appliance terminal being a terminal of afirst electrode and a second primary appliance terminal being a terminalof a second electrode, and wherein the method further comprises thesteps of: applying a voltage across the first primary appliance terminaland the second primary appliance terminal, monitoring the voltage acrossthe first primary appliance terminal and the second primary applianceterminal, and determining, in accordance with a short-circuit across thefirst primary appliance terminal and the second primary applianceterminal, that liquid is present across the first electrode and thesecond electrode.
 47. The method according to claim 43, wherein themethod further comprises, in accordance with determining that liquid ispresent in the appliance interface, the steps of: transmitting a devicesignal to an accessory device comprising a graphical user interface, andindicating the presence of liquid in the graphical user interface.
 48. Amedical device comprising: an electronic system for detecting presenceof liquid in an appliance interface, the system comprising: an applianceinterface comprising: a primary appliance terminal, a referenceappliance terminal, and a dielectric region separating the primaryappliance terminal and the reference appliance terminal; and anelectronic device couplable to the appliance interface, the electronicdevice comprising: a primary device terminal configured to connect tothe primary appliance terminal, and a reference device terminalconfigured to connect to the reference appliance terminal, wherein theelectronic device is configured to generate and apply an electricalreference signal to the reference appliance terminal, detect anelectrical primary signal from the primary appliance terminal, comparethe primary signal with the reference signal, and in accordance with atleast a component of the primary signal being identical to the referencesignal, determine that liquid is present in the appliance interface. 49.The medical device according to claim 48, comprising an ostomyappliance.
 50. The medical device according to claim 48, comprising awound dressing.
 51. The medical device according to claim 48, comprisinga urinary catheter.